Hi Tobias, thanks for thinking along!
My admin account has access to everything.
But I had left one thing untested: an incognito window.
And lo and behold: it works there, both for my test account and for admin.
So then I thought some setting in my regular browsers must be interfering, like maybe my AdBlocker ‘preventing pop-ups’, but I’m using my regular browser with AdBlocker for this Discourse instance as well, and ‘search’ works here on Meta - but not on mine.
So that would imply a setting in my Discourse instance - one that also affects performance in safe mode.
Hang on… that wouldn’t explain it working in incognito… dang…
Does anything come to mind for you?
Edit: The adblocker does interfere.
For a moment there i thought that resolved everything, but unfortunately not…