Read articles becoming unread on next load

Has anyone else been recently having issues with read articles? For me, the problem is that after clearing a list and exiting Newsblur, the next time I open, a number of read articles appear again in the list as unread. I haven’t been able to discern whether it’s any specific pattern to the unread articles, but they do seem to be more recent ones (I saw the old 2021 problem report about someone who said the unreads were odd numbers, or some pattern, but I don’t think that’s similar to my issue).

I’m using the Web client (Windows, Chrome), List view, and an example feed is The Guardian

Preference: Mark stories as read when scrolled past

I’ve tried various things like leaving the window open for a minute after switching to another feed, etc. to make sure it isn’t a me/network thing; and reloading/refreshing the feed to make sure it’s updating and sending the read receipts…