This MediaWiki-based wiki has been running for some years without issues. I added the HitCounters extension when that was removed from the main software install; again, no issues until recently.
A few days ago I updated the site to version 1.38.1. HitCounters extension is 0.3.4.
in Special Pages -> Popular Pages, all pages show the same (large) hit count as the site's Main Page.
The hit count at the bottom of each page is still correct, and increments when the page is refreshed.
I assume the bug was not there with the previous MediaWiki version 1.37.1, I think I would have noticed.