[GELÖST] Font Awesome not loading/Header appearing twice

The font awesome icons are no longer loading on my staging site. I have searched all the forum posts but cannot find a solution. I set font awesome to local in the Astroid plugin settings, but still no change.
I also have an issue with the sticky header - when I scroll down and back up, I get a second header appearing (see screenshot).
I have updated the Astroid plugin to 3.3.5, the template to 2.6 and the uikit modules to latest version. I am running PHP 8.2 and Joomla is 4.4.6. (which I want to move to Joomla 5). I have updated all other 3rd party components/plugins to latest versions.
URL: j52.longtermrentalsinfrance.com/
 

In the Astroid plugin, switch to CDN, save, then switch back to local and save again. Afterwards, test whether the fonts are displayed correctly. For the header, go to the template options and check if the header appears twice in the layout. Delete the duplicate section.

The header issue might also be caused by the color being transparent. Go to the template options, then to Colors /Header an Sticky Header (Backround Color). Double-check the color, reset it, and save.

Thank you for replying. Well saving the Astroid plugin in CDN and then Local hasn't helped the problem with the fa icons, but it has solved the issue with the header (or perhaps that was because I deleted the browser cache).
Just a thought, is the order of the Astroid plugin important (so first or last)?
Also, in the compiled.css file it seems to be calling "Font Awesome 7 free" (screenshot 6) - but in my staging site media/vendor/fontawesome-free/fontawesome.css the font awesome referred to is Font Awesome Free 5.15.4 (screenshot 7). Could this be an issue?
I appreciate your help on this.

Fonts are loaded by Joomla. It seems some extension on your system is loading these fonts and overriding your defaults. Have you specified anything in your custom.css file to load different fonts? 

I don't think so, but I will go through all of the plugins/components and disable them one by one to find the culprit.

Also, I don't know if it is related, but the animation for the preloader icon has stopped working. There is just a static icon.

Hello, what icons are not shown??
Please take in mind that in joomla 5.4 the font awesome version has changed. Please check the new syntax on the font awesome website