i know that this is an older topic – but with that new logic to show only Cat A and Cat B if both is true. Filter does not work as expected.
It shows the posts of that Category which has a post.

put this to your child-theme functions.php:

function my_avf_customize_heading_settings( array $args, $context, array $extra_args = array() ){
  if( $context == 'avia_sc_toggle' ){
    $args['heading'] = 'h3';              
  }
  return $args;
}
add_filter( 'avf_customize_heading_settings', 'my_avf_customize_heading_settings', 10, 3 );

if you only want to show a custom side bar – see what the custom sidebar is named and put this to your child-theme functions.php:

– this will activate the sidebar for single post – if you do not like to set it in enfold options – you can use more detailed conditional tags

function avia_change_layout_for_searchresults($layout, $post_id) {
    if( is_single() ) {
        $layout['current'] = $layout['sidebar_right'];
        $layout['current']['main'] = 'sidebar_right';
    }
    return $layout;
}
add_filter('avia_layout_filter', 'avia_change_layout_for_searchresults', 10, 2);

// next will activate the custom sidebar by its name 
add_filter("avf_custom_sidebar", function($custom_sidebar) {
    if( is_single() ) {
        $custom_sidebar = "Custom-Sidebar-Name"; 
    }
    return $custom_sidebar;
}, 10, 1);

Have you adjusted the settings here to suit your needs? : on Dashboard – Settings – General – “Date Format”

if that does not work – try in your child-theme functions.php:

function new_date_format() {
  $date_format = "m/d/y";
return $date_format;
}
add_filter('avf_datepicker_dateformat', 'new_date_format');

and if you like to influence the placeholder text:

function new_date_placeholder() {
  $placeholder = "TT / MM / JJ";
return $placeholder;
}
add_filter('avf_datepicker_date_placeholder', 'new_date_placeholder');

PS: for Formatstring see: https://wordpress.org/documentation/article/customize-date-and-time-format/

ok – sorry that is the other Events Plugin.
Seems that both plugins: Events Manager and Events Calendar got this feature of “Add to calendar”

And maybe it is better to get rid of the whole wrapper :

#top .tribe-events-c-subscribe-dropdown__container {
  display: none !important;
}

try – because it seems only be shown on single events page:

#top.single-event .em-event-add-to-calendar {
  display: none;
}

Are you able to influence the trigger? why don’t you use a.avia-button
or would you like to differentiate which buttons were clicked? In this case, you have to use the generated unique class as a trigger for each button element. f.e. a.av-av_button-60d3b58ef6e39d033d89831f5df0c979 – you can see that on dev tools what unique class is added.

Next: you can use that custom class on the anchor element itself by having a child-theme buttons.php.
if you would like to have that solution – you only have to edit that buttons.php to add the {$meta['el_class']} to the anchor too.

see: https://pastebin.com/jT1B5XJa
on line 758 i added that class as custom-class-button (which is added on line 764 to the wrapper element)

disadvantage of this quick change: if two custom classes are assigned – only the last one receives this addendum

(if you do not know how to use child-theme alb elements – tell me – or look to https://kriesi.at/documentation/enfold/intro-to-layout-builder/#customization )

See: https://webers-testseite.de/button-class-to-anchor-tag/
–

Thenn you can use as trigger (in this case) : a.conversion-button

next : did you use a grafic tool to replace jpgs with webp images?
the small view image is shown as jpg file ( with source webp )
Have you checked the settings – if there is a compression level for this replacement?
( 500×750 not blurry and 470px × 705px (scaled to 200px × 300px) blurry ) – so scaling might be a problem too.

Honestly, I think it would be an improvement to have an element that could contain other ALB elements, but is not itself a full-width element, and thus allows a sidebar to be placed next to it. Benefit is on that a possibility to have common background-image. Etc.

by the way – if your logo svg is well designed – you can change on inline svg fillings with quick css.
because you do not have a shrinking header – you can use for that the header class: av_header_transparency

f.e.:

.av_header_transparency .logo .st0 {
   fill: #4e4e4e
}

and here you can see the benefit of reworking the svg code – that class ( or there might be other path on that page) are allways the same for standard Illustrator setting.
_______________

btw: if you got a shrinking header you can use the class on html in combination with the class header-scrolled.

.html_header_transparency #header:not(.header-scrolled) .logo .st0 {
  fill: #4e4e4e
}

Just for info: I always recommend reworking the code of Illustrator-generated svg. Illustrator assigns a standard class with a counting index (st0, st1, st2 etc.). Unfortunately, if there are several inline svg on a page, the last svg on the page determines the properties of the class. Just css.
Either you edit the svg in a good text editor, or you define your own graphic styles in Illustrator for the fillings of the graphic elements. The graphic styles are then transferred to the svg code as a class.

but all downloads of that page you mentioned https://kriesi.at/documentation/enfold/icon/#download-fontello-or-flaticon-icons-included-in-enfold-demos are zip files that could be uploaded directly to enfold on enfold-child – import/export – Iconfont Manager
i tested it with the medical zip – and it works with no problem.
You had to upload that zip file without unpacking that file.

for those videos – best would be to have as selector a custom class if you like.
the best Way is to enter the aspect ration values to the element itself.
To show you for that page – that it is possible: – the aspect ratio of your video is on that: 1500/844 = 1.78

.avia-video.av-7fxcr-5428f1f56eaafaaab4a35f67598764cf,
.avia-video.av-lt51yanl-0fcc2bc8059b72cc4fbc0bf7e143adfe {
  padding-bottom: 178%;
}

that is what happens (calculation of that padding-bottom value) if you enter those correct ratios to the Element:

can you please test that snippet!
if you like to have 4 columns – just change it.

if you like to show the blog – then the context is not archive – it is index then ;)

PS: alb element = advanced layout builder element : if you use that – the element itself got some options to define the thumbnail size which is used.
but, as I suspected, you are not using this option

on Enfold : where did you load your jQuery in the header or have you set to load jQuery in the footer?
hasClass belongs to jQuery – but if you load jQuery later than there will be this error. Maybe your plugin has the option too – to load the scripts later.