Hey Mike,
Wow – thanks for your weekend support :)
Unfortunately, it didn’t make a difference.
We use the paid version of LayerSlider 7
Also WPRocket and cleared that too.

Here is my complete CSS List. It’s at the top but also tried at the very end.

/* –AS– Menu font color for transparent header */
#top #header.av_header_transparency #header_main .phone_number a {
color: #000 !important;
}

/* –AS– Shortcode Ultimate button text style */
.su-button-text-xl {
font-weight:800,, font-size:18px;
}
/* –AS– Making font “normal” for the main menu */
#top .av-main-nav > li > a {
font-weight: normal !important;
}
/* — AS — SHOWS ACTIVE PAGE IN MENU — */
.av-main-nav>li.current-menu-item>a>.avia-menu-text,.av-main-nav>li.current-page-ancestor>a>.avia-menu-text {
color: #00CCFF !important;
}

/* –AS– Making sub-menu font 15px */
#top .av-subnav-menu li a {
font-size: 30x;
}

/* –AS– Making active sub menu blue */
ul.sub-menu .current-menu-item .avia-menu-text span {
color: #049bd6 !important;
}

/* –AS– stretching the pulldown menu to 280 px */
.main_menu .menu ul { width: 280px; }

/* — AS — MAX MENU SIZE ADJUSTMENTS —
#top #header .avia_mega_div > .sub-menu.avia_mega_hr {
padding-top: 5px;
}
#top #header .avia_mega_div > .sub-menu {
padding: 20px 20px 20px;
}
*/

/* — AS — REMOVE CAPITAL FROM H1-H2 */
h1, h2, h3 {
text-transform: none !important;
}

/* — AS — TABLE ALIGN LEFT SET — */
.avia-data-table td {
text-align: left !important;
}

/* –AS– Reducing spaces between columns */
#top .av-flex-placeholder {
width: 1%!important;
}

/* –AS– HR HTML code in red */
hr { display: block; height: 2px;
border: 0; border-top: 1px solid #00CCFF;
margin: 1em 0; padding: 0;
}

/* — AS — DRAW A VERTICAL LINE — */
div.vr-right{
width: 1px; /* Line width */
background-color: red; /* Line color */
height: 100%; /* Override in-line if you want specific height. */
margin-left: 7px;
margin-right: 7px;
float: right; /* Causes the line to float to left of content.
You can instead use position:absolute or display:inline-block
if this fits better with your design */
}

div.vr-left{
width: 1px; /* Line width */
background-color: red; /* Line color */
height: 100%; /* Override in-line if you want specific height. */
margin-left: 7px;
margin-right: 7px;
float: left; /* Causes the line to float to left of content.
You can instead use position:absolute or display:inline-block
if this fits better with your design */
}

/* — AS — SLIDER ADJUSTMENT — */
.caption_framed .slideshow_caption .avia-caption-content p, .caption_framed .slideshow_caption .avia-caption-title, .avia-caption .avia-caption-content p, .avia-caption .avia-caption-title {
background: transparent;
}

/* — AW — IMA COURSE TABLE — */
.ima-courses .pricing-table-wrap:nth-child(1) .avia-heading-row { background-color: #00CCFF !important; font-size: 18px;}

.ima-courses .pricing-table-wrap:nth-child(2) .avia-heading-row { background-color: #00A0D0 !important; font-size: 18px;}

.ima-courses .pricing-table-wrap:nth-child(3) .avia-heading-row { background-color: #004080 !important; font-size: 18px;}

.ima-courses .pricing-table-wrap:nth-child(4) .avia-heading-row { background-color: #002C50 !important; font-size: 18px;}

.ima-courses .pricing-table { margin-left: 0 !important; padding: 0px 0 !important; }

.ima-courses .pricing-table>li { min-height: 70px; }

/* — AW — Hide Full-Width Menu on Mobile
@media only screen and (max-width: 768px) {
#top .av-submenu-container { display: none !important; }}
— */

/* –AS– Menu font color for transparent header */
#top #header.av_header_transparency #header_main .phone_number a {
color: #000 !important;
}

/* — AW — Mobile Friendly Likert Scale WP Forms — */
@media only screen and (max-width: 760px),
(min-device-width: 768px) and (max-device-width: 1024px) {

.wpforms-field-likert_scale table,
.wpforms-field-likert_scale thead,
.wpforms-field-likert_scale tbody,
.wpforms-field-likert_scale th,
.wpforms-field-likert_scale td,
.wpforms-field-likert_scale tr {
display: block !important;
}
.wpforms-field-likert_scale th {
padding-left: 6px !important;
font-weight: bold !important;
}
.wpforms-form thead tr {
position: absolute !important;
top: -9999px;
left: -9999px;
text-align: left !important;
}
.wpforms-field-likert_scale tr {
border: 1px solid #ccc !important;
}
.wpforms-field-likert_scale td {
border: none !important;
border-bottom: 1px solid #eee !important;
position: relative !important;
padding-left: 50% !important;
}
.wpforms-field-likert_scale td:before {
position: absolute !important;
top: 6px !important;
left: 6px !important;
width: 45% !important;
padding-right: 10px !important;
white-space: nowrap !important;
}
.wpforms-field-likert_scale td:nth-of-type(1):before {
content: “Not yet”;
}
.wpforms-field-likert_scale td:nth-of-type(2):before {
content: “Planning stage”;
}
.wpforms-field-likert_scale td:nth-of-type(3):before {
content: “In developing”;
}
.wpforms-field-likert_scale td:nth-of-type(4):before {
content: “Yes, for 1-3 years”;
}
.wpforms-field-likert_scale td:nth-of-type(5):before {
content: “Yes for more than 3 years”;
}

/* –AS– Menu font color for transparent header */
#top #header.av_header_transparency #header_main .phone_number a {
color: #000 !important;
}
Not sure what else I can try.
Thanks a lot
Axel

Great idea – thank you Guenni007

Have a look at https://fyrholtrejser.dk/rejser/test/ where you see the Sticky Submenu in action.
I am controlling the font size in this menu with the following CSS:

#top .av-subnav-menu li a {
font-size: 17px;
}

How do I make the active menu item underlined only in this Sticky Submenu?

Hello Ismael,
thank you for your hint.
Unfortunately, I really cannot find where I could adjust that setting. I find no place in the styling section that controls that specific element.
There is a box called All Headings [H1-H6] but it does not contain font size settings. Then there is a box for Heading H3 which sets font size to 20.
But I cannot find any settings for the specific element “Special Title”. The two titles in the two pages I mentioned are both in a “Special Title” content element and are both set to H1.
I have the same problem elsewhere. This page page link there are three main titles. They are all in Special Title content elements and all are set to H1, but the one in the middle appears bigger then the others.
Can you help please?

Best regards,
Elena

Thank you Mike, I added the code for the table of contents as well

.single-post .entry-content li {
font-size: 18px !important;
}

I can see the single post entry has changed so just waiting the hosting cache to catch up for the table of contents, appreciate the help.

Andrew

/*sidebar text sizes*/
.news-link { font-size: 14px; font-weight: 100 !important; }
Sorry actually this was the successful code to change the size.