This is something you decide when you create the page/post. In other words, in the editor of the post itself. There you will find the option to customize the layout on the right-hand side.

This may look slightly different in block editor mode, but is also available there.

However, this setting only makes sense if there is also something below the header (an image, a slider, etc.).
Therefore, this setting is not preset by default.

Now to Montserrat. If you download the font from Google : you have inside the zip file the variable font files and those static font files and indeed the internal Font Name is: Montserrat thin.
if you look at : https://caniuse.com/variable-fonts you see that it is now quite possible to work with variable fonts. Whether you need all these features – and Montserrat is one of these lavishly equipped variable fonts – is up to you to decide. If only a few fonts (300, 400, 700) are needed on the website, I think it is better to use the static fonts.
And comparing the difference between normal and italic Font it seems there will be no big difference on browser rendered italic font and embedded italic font. So it might be enough to use only those static font files.

Here are both zip files prepared to upload to enfold font manager:
( all will have ttf and woff2 inside – that will be enough for all browsers (ttf as fallback if there are very old browsers only on users desktop installation))

• Montserrat varible: Link
• Montserrat static: Link

on Font Manager it will look like this ( choose or use both with this https://kriesi.at/documentation/enfold/typography/#using-variable-fonts )

how did you embed the Montserrat Font?
on your Enfold – @font-face rules of the other pages (not team page) i can only find Montserrat Thin Regular. (400) and no 800 style. So your font-weight set to 800 is only browser rendering.

Next : that team page loads 15 rules @font-face – if i switch off that css in the dev tools – the Team will be normal as the other items.
Where does that come from? Are these loaded by that feed? Maybe it is possible to instruct that feed ( is it a plugin? ) to use the theme fonts. Then we can load a better prepared Montserrat Font.

! As far as i know – you can choose on generating the template for that feed use as font: “Standard”- and that means it uses the theme fonts.

__________

/* cyrillic-ext */
@font-face {
  font-family: 'Montserrat';
  font-style: italic;
  font-weight: 400;
  src: url(https://fonts.gstatic.com/s/montserrat/v26/JTUFjIg1_i6t8kCHKm459Wx7xQYXK0vOoz6jq6R9WXV0oJC8MLnbtrVK.woff) format('woff');
  unicode-range: U+0460-052F, U+1C80-1C8A, U+20B4, U+2DE0-2DFF, U+A640-A69F, U+FE2E-FE2F;
}
/* cyrillic */
@font-face {
  font-family: 'Montserrat';
  font-style: italic;
  font-weight: 400;
  src: url(https://fonts.gstatic.com/s/montserrat/v26/JTUFjIg1_i6t8kCHKm459Wx7xQYXK0vOoz6jq6R9WXx0oJC8MLnbtrVK.woff) format('woff');
  unicode-range: U+0301, U+0400-045F, U+0490-0491, U+04B0-04B1, U+2116;
}
/* vietnamese */
@font-face {
  font-family: 'Montserrat';
  font-style: italic;
  font-weight: 400;
  src: url(https://fonts.gstatic.com/s/montserrat/v26/JTUFjIg1_i6t8kCHKm459Wx7xQYXK0vOoz6jq6R9WXd0oJC8MLnbtrVK.woff) format('woff');
  unicode-range: U+0102-0103, U+0110-0111, U+0128-0129, U+0168-0169, U+01A0-01A1, U+01AF-01B0, U+0300-0301, U+0303-0304, U+0308-0309, U+0323, U+0329, U+1EA0-1EF9, U+20AB;
}
/* latin-ext */
@font-face {
  font-family: 'Montserrat';
  font-style: italic;
  font-weight: 400;
  src: url(https://fonts.gstatic.com/s/montserrat/v26/JTUFjIg1_i6t8kCHKm459Wx7xQYXK0vOoz6jq6R9WXZ0oJC8MLnbtrVK.woff) format('woff');
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;
}
/* latin */
@font-face {
  font-family: 'Montserrat';
  font-style: italic;
  font-weight: 400;
  src: url(https://fonts.gstatic.com/s/montserrat/v26/JTUFjIg1_i6t8kCHKm459Wx7xQYXK0vOoz6jq6R9WXh0oJC8MLnbtg.woff) format('woff');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
/* cyrillic-ext */
@font-face {
  font-family: 'Montserrat';
  font-style: normal;
  font-weight: 400;
  src: url(https://fonts.gstatic.com/s/montserrat/v26/JTUSjIg1_i6t8kCHKm459WRhyyTh89ZNpQ.woff2) format('woff2');
  unicode-range: U+0460-052F, U+1C80-1C8A, U+20B4, U+2DE0-2DFF, U+A640-A69F, U+FE2E-FE2F;
}
/* cyrillic */
@font-face {
  font-family: 'Montserrat';
  font-style: normal;
  font-weight: 400;
  src: url(https://fonts.gstatic.com/s/montserrat/v26/JTUSjIg1_i6t8kCHKm459W1hyyTh89ZNpQ.woff2) format('woff2');
  unicode-range: U+0301, U+0400-045F, U+0490-0491, U+04B0-04B1, U+2116;
}
/* vietnamese */
@font-face {
  font-family: 'Montserrat';
  font-style: normal;
  font-weight: 400;
  src: url(https://fonts.gstatic.com/s/montserrat/v26/JTUSjIg1_i6t8kCHKm459WZhyyTh89ZNpQ.woff2) format('woff2');
  unicode-range: U+0102-0103, U+0110-0111, U+0128-0129, U+0168-0169, U+01A0-01A1, U+01AF-01B0, U+0300-0301, U+0303-0304, U+0308-0309, U+0323, U+0329, U+1EA0-1EF9, U+20AB;
}
/* latin-ext */
@font-face {
  font-family: 'Montserrat';
  font-style: normal;
  font-weight: 400;
  src: url(https://fonts.gstatic.com/s/montserrat/v26/JTUSjIg1_i6t8kCHKm459WdhyyTh89ZNpQ.woff2) format('woff2');
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;
}
/* latin */
@font-face {
  font-family: 'Montserrat';
  font-style: normal;
  font-weight: 400;
  src: url(https://fonts.gstatic.com/s/montserrat/v26/JTUSjIg1_i6t8kCHKm459WlhyyTh89Y.woff2) format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
/* cyrillic-ext */
@font-face {
  font-family: 'Montserrat';
  font-style: normal;
  font-weight: 700;
  src: url(https://fonts.gstatic.com/s/montserrat/v26/JTUSjIg1_i6t8kCHKm459WRhyyTh89ZNpQ.woff2) format('woff2');
  unicode-range: U+0460-052F, U+1C80-1C8A, U+20B4, U+2DE0-2DFF, U+A640-A69F, U+FE2E-FE2F;
}
/* cyrillic */
@font-face {
  font-family: 'Montserrat';
  font-style: normal;
  font-weight: 700;
  src: url(https://fonts.gstatic.com/s/montserrat/v26/JTUSjIg1_i6t8kCHKm459W1hyyTh89ZNpQ.woff2) format('woff2');
  unicode-range: U+0301, U+0400-045F, U+0490-0491, U+04B0-04B1, U+2116;
}
/* vietnamese */
@font-face {
  font-family: 'Montserrat';
  font-style: normal;
  font-weight: 700;
  src: url(https://fonts.gstatic.com/s/montserrat/v26/JTUSjIg1_i6t8kCHKm459WZhyyTh89ZNpQ.woff2) format('woff2');
  unicode-range: U+0102-0103, U+0110-0111, U+0128-0129, U+0168-0169, U+01A0-01A1, U+01AF-01B0, U+0300-0301, U+0303-0304, U+0308-0309, U+0323, U+0329, U+1EA0-1EF9, U+20AB;
}
/* latin-ext */
@font-face {
  font-family: 'Montserrat';
  font-style: normal;
  font-weight: 700;
  src: url(https://fonts.gstatic.com/s/montserrat/v26/JTUSjIg1_i6t8kCHKm459WdhyyTh89ZNpQ.woff2) format('woff2');
  unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C0, U+2113, U+2C60-2C7F, U+A720-A7FF;
}
/* latin */
@font-face {
  font-family: 'Montserrat';
  font-style: normal;
  font-weight: 700;
  src: url(https://fonts.gstatic.com/s/montserrat/v26/JTUSjIg1_i6t8kCHKm459WlhyyTh89Y.woff2) format('woff2');
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}

Authors only can edit own posts/portfolios but never pages. If you like to have different permissions – you need to install a plugin.

next hint: to bring a heading to center position – you do not need to have three 1/3 columns with the heading inside the middle column!
You see that your “Willkommen” heading is cut-off on both sides. Put it in a 1/1 column. Because you got a modern centered setting it will work with no problem.

you got a ruleset :

div .av-arrow-down-section .av-section-color-overlay {
  bottom: 24px;
}

Question: does it make sense on having on the last color-section an arrow down ?
I guess if you delete this option you do not need to change that ruleset.

remove that div with the ID overview – it creates an ugly break in your background-image (by adding a after_section_1 container)
Give the second color-section the ID : overview. Set the min-height to 280px.

On activating that section in the dom to be seen in its dimension- you can see that 280px will touch the top- and the next grid-row will be visible beneath the header:
(click to enlarge that image:)

the grid-row shown now under the second color-section because parallax shift have moved it to that place – but you see that is not under the header!

PS: i would determine the min-height of that second color-section not via the Color-Section Options! but via quick css – because on mobile you have different circumstances and have to set media-queries on this to have no min-height and no background-image – and a very small height.

That is normal behaviour of WordPress Users.
Authors only are able to edit own posts (no pages). Editors can edit all Posts and Pages.
and as an admin – well – of course everything

An Author logged in see:

Only on “mine” Posts on hovering there is an edit Button.
If you show all Posts – you can not see any edit Button at all on Posts from different Users.

Comments etc. are only listed – and can not be edited (except on own Posts) etc.

Have you installed a Plugin on influencing User Roles? I can not believe that Authors are able to see pages.

By the way @Ismael : that link to show the available Fonts “Google Webkit Fonts” does not work anymore.
Reason is that Droid Fonts and Open Sans Condensed is not listed in Google anymore.

where did you get your font from? Is it a download from Google? Offers Google a variable font on that download?

The macosx comes from those invisible files OSX is generating for a lot of files ( some are icons etc. and meta infos ). Packing these folders by OSX internal zip – these files are inside that zip too.
BetterZip for example can zip folders without those meta info files ( it is called: pack for PC ).

After your Answers – i will try to give a good explanation on how you do it.
If you downloaded an otf or ttf file – try: https://kriesi.at/support/topic/eigene-schrift-einbetten/#post-1401545

But Font-Icons are monochrom ! – if you downloaded colored Icon-Packs – then you can not use them as font-icons in Enfold.
__
the downloaded flaticons folders – do they have a svg font icon?
you can extract that svg and upload it to fontello icon: https://fontello.com/
drag and drop that svg file to “custom icons” field. I guess you can do that for each of your Icon-Packs. And make one Container File of them.

After uploading all of your svgs to that input field – activate all of them – Name your font – and download it. This zip is for uploading it to Enfold.

set up for mobile devices :

.responsive.avia_mobile #top .av-large-gap.av-fixed-size .av-masonry-entry .av-inner-masonry {
    right: 20px;
    bottom: 20px;
}

or if you mean for small screens – then a media-query is the means of choice instead:
f.e.:

@media screen and (max-width: 767px) {
  #top .av-large-gap.av-fixed-size .av-masonry-entry .av-inner-masonry {
      right: 20px;
      bottom: 20px;
  }
}

choose the large gap and place that css into your child-theme quick css:
(masonry-gallery – or do you mean the masonry-entries?)

#top .av-large-gap.av-fixed-size .av-masonry-entry .av-inner-masonry {
    right: 50px;
    bottom: 50px;
}

i try to find a solution for av-flex-size now…

nicht mit dem svg als img tag. Wenn da ein inline svg wäre, dann könnte man sogar auf das image overlay verzichten.
wenn du nochmal auf meine Beispielseite gehst: https://webers-testseite.de/ausgesonnen/
und dir jetzt den leicht geänderten Quellcode des svg ansiehst, dann bemerkst Du, dass jetzt jede Zeile eine eigene Klasse hat.
Diese sind via quick css ansprechbar.

.ideen-batch svg {
  width: 20vw;
  margin-left: 10vw;
} 

#av_section_1:hover .ideen-batch svg .sichtbar {
  fill: #FFF;
  transform: scale(1.2);
  transform-origin: center 90px;
}

#av_section_1 #Ideen-Kreis :not(.kreis) {
  opacity: 0;
  animation: batch 1s ease 3s forwards;
}

@media only screen and (max-width: 549px) {
  #av_section_1 {
    background-position: 75% 100%;
  }
  .ideen-batch svg,
  .ideen-batch .avia_image {
    margin-left: 3vw;
  }
}

@keyframes batch {
  to {
    opacity: 1;
  }
}

add a sufficient line-height to it:
( i think the font-size you set in the heading itself – so better is to use a relative line-height value)

h6 {
  line-height: 1.7em;
  font-weight: 400 !important;
  letter-spacing: 0.01em !important;
  background: linear-gradient(to right, #b04938, #ddbbae, #b8b665);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}