At https://www.mediawiki.org/wiki/Talk:Beta_Features/Hovercards only 1 additional batch of topics is loading. I scroll to page-end twice, and it says "No older topics". There are many older topics, that should be loading. They can be seen and accessed in the history, https://www.mediawiki.org/w/index.php?title=Talk:Beta_Features/Hovercards&dir=prev&action=history
No other boards seem to be affected.
Description
Description
Related Objects
Related Objects
Event Timeline
Comment Actions
This is probably T114456: Main topic list pagination can only paginate at most 500 topics (less sometimes, apparently due to moderation), exacerbated by many moderated topics (IIRC there was a massive spam problem on this page at one point).