on former times that css declaration of background-attachment: fixed is not well supported – and:

Since March 2022, this feature works across the latest devices and major browser versions (Learn more about Baseline)
Most mobile devices have a delay in updating the background position after scrolling a page with fixed backgrounds.

That is the reason why Enfold decided before this time to transform it to a background-attachment : scroll – maybe a test if it will work could be insteresting.

See here a complex Solution using a trick: https://webers-testseite.de/visual-artist/

• Starting with the setting of background-attachment : scroll
• i gave to each of those color-section a custom class: bg-fixed
• i create the pseudo-containers for those bg-fixed sections : before
• These bg-fixed:before container inherited the background-image from its parent.
• These bg-fixed:before container are set to position: fixed ! ( this is well supported on mobile devices )
• to have no overflow – i set a clip-path to each of those color-sections that will cause the slanted boarder

etc. indeed complex – check the mobile behaviour.

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;
}

Classes such as av_one_third are just names. With these names, “Enfold” knows how to handle them, e.g. how to set the width.
But nobody prevents you from treating them differently.
So you can use 1/3 columns and use them with all the options within the Advanced Layout Builder element. And then, later on, re-declare the settings provided by Enfold.

To address them better and not influence the others (e.g. 1/3 columns), a custom class would be useful. To use a container as flex container – it would be advisable to have only those elements inside that should be influenced.
Short and concise – create a color-section (custom class- what you like : flex-six) with 6 1/3 containers inside – without equal-height option.
the direct parent container to those columns is the entry-content-wrapper – so this has to be the flex container.

see and get css-code : https://webers-testseite.de/six-column-flex-layout/

PS : Please remember to define the parallax effects differently for the screen widths.
Why 1/6 columns and smaller were not adopted by default, you can see from the example.