Some topics that are read, inluding one authored by me, are listed as unread by me

It’s the one and only topic that I published, nineteen hours ago, before retiring (yesterday) from administration. Previously in a private category (either our Staff area or Private lounge):

More than a month old, I have no recollection of contention – as far as I recall, zero response to the topic (neither a like, nor a dislike, in the weeks when it was available to local staff). I’ll be extremely surprised if any post was added then deleted. @simonv3 please, can you take a look? Thanks.