Probably not the reason, but worth to do a quick check:
Sometimes the update cache interferes, so if something's odd with updates - some module (or core) claims to have updated, but then...
The issue with checking for updates in the BackdropCMS dashboard makes website development and maintenance more difficult. I manage more than ten websites hosted by two different providers, one...
Yep. Just add the 'Global: Random' Sort Criteria.