It looks like PLBot is having some sort of problem, see here: https://www.wikidata.org/w/index.php?title=Template:Property_uses&diff=prev&oldid=1970046203
This is effecting the usage history tracking of properties and the display of property coverage on Property discussion pages.
Thanks for these tools btw, they're very useful to me! :D
Thank you for your report. I will have a look at this situation within the next days. This is indeed broken for some reason.
The issue was resolved here: https://phabricator.wikimedia.org/T347284.
Overall, the job is still in a wonky state and it could fail again, but for other reasons than the issue in the phab ticket. I am currently reorganizing jobs of PLbot and DeltaBot to a hopefully more stable and maintainable configuration, but until this is completed, things can fail sometimes...