Then test the archive page again. If the problem is resolved in his test, reactivate your theme, plugins and code snippets one by one, testing each time until the problem returns. That should help give you an idea of where the conflict occurs.
I don't think it's related to a Facebook script either, but that is not what I'm referring to. Our consoles show different messages. I am looking at the link you shared previously, in Chrome, while visiting as a Guest (logged-out of WP): hidden link
I am referring to this error in custom-scripts.js:
custom-scripts.js:1 Uncaught ReferenceError: jQuery is not defined
(anonymous) @ custom-scripts.js:1
I have attached a full-screen screenshot so you can see exactly what I see. It seems custom-scripts.js is loaded before jQuery is available. Maybe this file is enqueued in the child theme without jQuery in its dependencies?