have a look into your child-theme functions.php if there is something like this:

add_action('ava_before_footer', function() { …

because it is everywhere on your installation – it seems to be inserted via a shortcode

i guess to make it in a propper way – it is hard stuff to create a custom post type (CPT).
See here f.e.: https://www.cloudways.com/blog/how-to-create-custom-post-types-in-wordpress/

to have an impression how many work this could be look inside : enfold/includes/admin/register-portfolio.php how enfold registers the portfolio post type.

Read here – if you need more help – tell me:
break-inside: avoid
https://enfold.webers-webdesign.de/multicolumn-text-block/
https://css-tricks.com/almanac/properties/b/break-inside/

nice to know

widows = minimum number of lines in a paragraph split on the new page.
orphans = minimum number of lines in a paragraph split on the old page.

Can you give us a link to that page?
Developer tools will tell us where it comes from. But best on doing that is to switch of merging and compression tools.

Yes you are right that on default “Elegant Red” – lato is set for default_font.
But did you change that on Enfold Options. Either by using a websafe font or by uploading Lato font with custom font manager ?

You can hamper Enfold from loading google fonts from google servers by:
(in child-theme functions.php:)

function my_output_google_webfonts_script( $activate ){
  return false;
}
add_filter( 'avf_output_google_webfonts_script', 'my_output_google_webfonts_script', 10, 1 );

yes – that they goes to the right side – but on iphone12 landscape you could not scroll to those items on the bottom !
If you set the overflow-y to auto or scroll the flyout will not be seen.

I for one test almost all my advice beforehand.
So as long as you have a lang attribute to html, it should work.
As I said – I don’t have Polylang running on a test installation, so I don’t know how Polylang switches between languages, but I can’t imagine the lang attribute not being set. WPML does it that way, anyway.

The lang attributes can be determined using the developer tools, and the path to the alternative logo must of course be replaced.
If you use transparent headers, which you didn’t mention, you won’t see the actual logo at the beginning.

if you try to substitute the transparency logo on some pages use

function replace_transparent_logo_on_some_pages($header){
    $currentlang = get_bloginfo('language');
    if($currentlang=="de-DE"){
        $header['header_replacement_logo'] = "/wp-content/uploads/YOUR_ALTERNATE_LOGO";
    }
    return $header; 
}
add_filter('avf_header_setting_filter','replace_transparent_logo_on_some_pages');

i tested this – but if there is set on “Transparency Options” a svg as logo – this will not replace this. It seems that the replacement of the img svg to an inline svg hampers that filter from changing the output.

i do not know if polylang has some classes on body for each language – but on htm there is that lang attribut you can check.
you then can use a filter to change logo with an if clause checking for lang:

function change_logo_by_lang($logo){
  $currentlang = get_bloginfo('language');
  if($currentlang=="en-GB"){
    $logo = "/wp-content/uploads/YOUR_LOGO_FILE.jpg";
  }
  return $logo;
}
add_filter('avf_logo','change_logo_by_lang');

by that you can even differ on f.e.: en-US, en-CA, en-AU, en-GB, en-UK

the new functions of Enfold for setting parallax effects on images – or columns are also active on mobile devices. Settings of e.g. an absolute positioning of an image are therefore also applied on the small screens. Therefore it might be advisable not to set the settings in the first screen but to set them for wide and medium screens only.

if you have set a relative or absolute position for the first screen width – this will be the default setting for all other screens (until you change it there).
My recommendation is to leave the first setting as it is – and only set position 1 and 2.

the Parallax effect increases this gap by making this column scroll faster than the rest as you scroll up.

Wahrscheinlich wirst du zu dem Topic nicht mehr zurückkehren – aber zur Klärung: Zunächst sehe ich als Participant wie du keine Private Content Area; dann kann ich an deinem Nick leider nicht sehen, ob du ein versierter professioneller Webdesigner bist und ob du schon diverse Lösungsansätze ausgeführt hast. Daher muss man hier bei jeder Anfrage die lediglich das gewünschte Ziel wage beschreibt davon ausgehen, das jemand eine Lösung sucht, der nicht viel Ahnung von der Materie hat.
Es ist immer nützlich so genau wie möglich die Problematik zu beschreiben.
Das hier

Logo oben links
Hauptmenü links darunter,

hätte ausgereicht um hinreichend die Situation zu beschreiben – und für mich mit dieser Testseite das Problem einzukreisen.
https://kriesi.at/themes/enfold-construction/

Das padding-left des ersten Menüpunktes auf Null zu setzen sollte theoretisch nicht ausreichen, um eine genaue Linksbündigkeit zu erzielen, da text-align der Menüpunkte auf zentriert steht.
Ich wäre einen anderen Weg gegangen, unter Wahrung der Menütext Zentrierung und der Äquidistanz der Menüpunkte.

_____________

You probably won’t return to this topic – but for clarification: First of all, as a participant like you, I don’t see a private content area; then, unfortunately, I can’t see from your nickname whether you are an experienced professional web designer and whether you have already carried out various approaches to a solution. Therefore, with every request here that merely describes the desired goal, one must assume that someone is looking for a solution who doesn’t know much about the subject.
It is always useful to describe the problem as precisely as possible.

Logo top left –
main menu left below

That would have been enough to describe the situation sufficiently – and for me to isolate the problem with this test page.
https://kriesi.at/themes/enfold-construction/

Setting the padding-left of the first menu item to zero should theoretically not be enough to achieve exact left alignment, as text-align of the menu items is set to centred.
I would have gone a different way, preserving the menu text centring and the equidistance of the menu items.

Welche WordPress Version hast du laufen? denn das wp-includes gehört zu WordPress!

ich habe über Google einige Einträge bezüglich NextGen Gallery gefunden.

if you got ftp access – go to your root directory and find in wp-includes that script-loader.php
something similar to this is no longer supported:

echo($str{0});
now there might be : echo($str[0]);

have a look what is on line 757