I hope you're doing well.
We're using Moodle 3.6 with the essential theme for many years now. Just today, we're having a very weird inconsistent issue.
"Sometimes" when we try to click the Add an activity or resource link (after turning the editing on) or open the course settings menu, nothing happens, simply a hashtag appears at the end of the URL and nothing opens. It seems that JS is not properly loaded. We're facing this issue since today morning, using different browsers and on different devices. We cleared the browsers and Moodle caches but still the same issue. As I mentioned above, sometimes it just works, and sometimes it doesn't.
We have restored backups from 3 weeks ago, and 1 week ago, and both these backups have the same issue. No plugins were installed, updated, or configured before the issue started to appear.
When we're checking the developer tab in Google Chrome we found errors, like "Uncaught Error: Mismatched anonymous define() module: function()..." check the attachment. But there's no indicator of what's causing this issue.
Again, I just want to stress that we have not done any recent installations, updates, upgrades, or major changes to any part of this installation of Moodle.
I hope you'll be able to help us out.