put this to your child-theme functions.php:

function ava_custom_script_mod_social(){
?>
<script>
(function($){
  $('#header').one('click', '.av-main-nav-wrap', function() {
      var isMobile  = $('.av-burger-menu-main').css('display'),
      isHeading = "Social Bookmarks",
      social    = $('#header_main .social_bookmarks').clone(true).addClass('sub-menu'),
      mobileMenu  = $('.av-burger-overlay');
      
      mobileMenu.find('#av-burger-menu-ul').append('<li class="only-burger menu-item-social av-active-burger-items"><a itemprop="url" alt="Social Bookmarks" style="" href="#"><span class="avia-bullet"></span><span class="avia-menu-text">'+isHeading+'</span><span class="avia-menu-fx"><span class="avia-arrow-wrap"><span class="avia-arrow"></span></span></span></a></li>');
    
      if( social.length ){
        mobileMenu.find('.only-burger.menu-item-social').append(social);
      }
    });
        
    var htmlString   = $('#socket .social_bookmarks').clone().find('li a'),
    socialString = [];

    htmlString.each(function() {
      var socialClass = $(this).parent('li').attr('class'),
      socialItems = $(this).wrap('<li class="'+ socialClass + ' menu-item menu-item-avia-special menu-social"></li>').parent().unwrap();
      socialString.push(socialItems);
    });
    var socials = socialString.reverse();

    $(socials).each(function() {
      $(this).appendTo('#avia-menu');
    });

    $('#avia-menu .menu-social').css('float', 'right'); 
})(jQuery);
</script>
<?php
}
add_action('wp_footer', 'ava_custom_script_mod_social');

if you do not like to have a heading on those bookmarks
replace that one line in the snippet above:

isHeading = " ",

then this to your quick css:

#av-burger-menu-ul .menu-item-social > a {
  pointer-events: none;
  margin-bottom: 10px;
}

#av-burger-menu-ul .menu-item-social a .avia-menu-text {
  font-style: italic;
}

.html_av-overlay-side-classic #top .av-burger-overlay li.menu-item-social a {
  border: none !important
}

.responsive #top #av-burger-menu-ul .social_bookmarks.sub-menu {
  margin-left: 30px;
  overflow: visible;
  float: left !important;
  display: block !important;
  height: auto
}

#av-burger-menu-ul .social_bookmarks.sub-menu li {
  display: block;
  margin: 3px 15px;
  float: left;
}

#av-burger-menu-ul .social_bookmarks.sub-menu li a {
  padding: 10px !important;
  display: table-cell !important;
  float: none !important;
  border-radius: 0 !important;
}

#av-burger-menu-ul .social_bookmarks.sub-menu li a:before {
  position: relative;
  font-size: 1.8em;
  top: 2px !important;
}

#top #wrap_all #av-burger-menu-ul .av-social-link-facebook a { padding: 10px 13px !important;}
#top #wrap_all #av-burger-menu-ul .av-social-link-facebook:hover  a{color:#fff; background-color:#37589b!important; }
#top #wrap_all #av-burger-menu-ul .av-social-link-instagram:hover a{color:#fff; background-color:#a67658!important; }
#top #wrap_all #av-burger-menu-ul .av-social-link-youtube:hover a{color:#fff; background-color:#a72b1d!important; }

if you do not want to have the burger nav horizontally centered :

#top #av-burger-menu-ul {
  vertical-align: top !important;
  padding-top: 150px !important;
}

result should be:

the package you can download from google on fonts that have “variable fonts” contains a subfolder with those static fonts.
Enfold could handle variable fonts – but you had to know how to work with those variable fonts.

if you only like to upload those static fonts – pull this folder form that zip file to your desktop – rename it to “Montserrat” and (important) zip it for PC ( not including the invisible OSX files generates with their compression options.). Betterzip f.e. has a drop-window where you can choose for what system you zip it.
Why this is important. if you upload that zipped file you will have an additional font in there:

__________________
Next : Google does only offer ttf files for you. but it might be better to upload woff2 files ( brotli compression ) as font-files.
( less loading times on woff2 ). So it might be good to have both woff2 ( for modern Browsers ) and ttf (for older browser support)
see: https://kriesi.at/support/topic/host-web-font-yourself-some-info/#post-1364066
use transfonter to generate woff2 and ttf files – put them in one folder – rename the folder to your needs ( Montserrat ) – and upload that.
As mentioned there – think if you realy need an italic font to upload – because browser rendering might do a good job to of normal font.

IF it is a WPML Page

there is on WPML Options a Setting for inserting the flags to menus:

You can add there lang switch to every menu you have declared on your system.
And you can set the look of them ( flag dimensions etc. )

Yes – or you use the enfold options dialog : General Styling – Socket :

please try : https://wordpress.org/plugins/force-regenerate-thumbnails/ as mentioned above – i guess this is the tool to recalculate all files by erasing the existing ones.

But be carefull – if you have inserted on your content an image with an image-size that will be deleted – you then have no image in the frontend.

The snippet above ensures that during the upload of new files, when creating the various file formats, some of the intended formats are no longer created.
This does not affect existing file formats.
For this you need these regenerate thumbnails plugins once to recalculate here and to remove file formats that no longer exist.
After recalculating you can deinstall those plugins.

that video is a background-video or a placed video element?

On video element try to set up a pseudo container – but best would be to set a custom class to the video

.avia-video .avia-iframe-wrap:after,
.avia-video .mejs-container:after {
  content: "";
  position: absolute;
  width: 100%;
  height: 100%;
  top: 0;
  left:0;
  background: linear-gradient(to bottom, rgba(255,255,255,0.01) 0%,rgba(6,133,229,1) 80%);
  opacity: 0.8;
  z-index: 5 !important;
  pointer-events: none;
}

Yes – on WPML this is the way – because we have on WPML for each language a separated Enfold Options Dialog. But i do not get an info – if it is a WPML Multilang Installation.

But : after erasing some of those image-sizes – you had to regenerate your thumbnails : there are some good plugins to do so.
f.e.: https://wordpress.org/plugins/force-regenerate-thumbnails/

does that solution work if burger menu is active?

on menu.js we got this setting:

/**
 * If we have burger menu active we ignore sticking submenus
 */
if( burger_menu.is(":visible") )
{
	this.css({top: 'auto', position: 'absolute'}); fixed = false;
	return;
}

so – if i like to have that – i prepare to have child-theme alb elements ( unfortunately some settings in menu.css are set to important, so that you have to drag along menu.php and menu.css as well. Actually only a menu.js would be necessary.)

is that a wpml page?
WPML got WPML CMS Nav to translate the menus.

first of all – your link does not work.

next on those alb elements ( grid-row and the cell that has the flip-box) set all paddings to zero. If you do not set – there will be default ones set by enfold.
Do not set min-height for those! – i used for grid-item that option : Inverse Layout – Ignored For Tooltip

give a custom class to the grid-row – i tested it with my setting : one-flipper

synchonize the break-point at media-query to the grid-row breakpoint.
i have set 767px but if you like you can do it with 989px

@media only screen and (min-width:768px)  {
  .av-layout-grid-container.one-flipper {
    min-height: 28.12vw;
  }
  .av-layout-grid-container.one-flipper .avia-icon-grid-container,
  .av-layout-grid-container.one-flipper .article-icon-entry {
    min-height: 28.12vw;
  }
}

@media only screen and (max-width:767px)  {
  .av-layout-grid-container.one-flipper .avia-icon-grid-container,
  .av-layout-grid-container.one-flipper .article-icon-entry {
    min-height: 56.25vw;
  }
}

now for understanding: your image has a 16/9 ratio because the image is set to cover the background hat to be of that aspect ratio.
the screenwidth is 100vw – and the height than must be in a 32/9 ratio ( because only the half container should be 16/9)
9/32 = 28.125
the whole grid-row now has to be 28.125vw in height !

Sample Page: https://webers-testseite.de/isp/
and css for normal flip

off-topic

btw. @yigit – on masonry gallery (see last code ) there is that one (4th) option missing to have “fixed manually”. Is there a reason for not having it on masonry_gallery ?
i think it would be nice to have on masonry gallery too!

to have tags for media-library images is easy to obtain:

function add_tags_for_attachments() {
    register_taxonomy_for_object_type( 'post_tag', 'attachment' );
}
add_action( 'init' , 'add_tags_for_attachments' );

so we could use landscape, portrait, landscape-large, portrait-large, square for them.

Well what you had to know is that you can redifine an existing enfold image size with an additional setting of crop or no-crop:

so you can use ismaels code with an additional setting :

function avf_customization_modify_thumb_size( $size ) {
      $size['entry_without_sidebar'] = array( 'width' => 9999, 'height' => 9999, 'crop' => false );
      $size['entry_with_sidebar'] = array( 'width' => 9999, 'height' => 9999, 'crop' => false );
      return $size;
}
add_filter( 'avf_modify_thumb_size', 'avf_customization_modify_thumb_size', 10, 1 );

After that recalculate thumbs – maybe that is the solution.