It is a known issue and devs and top witnesses are looking into it. The fix will be issued at some point soon (hopefully).
From what I know is that there is a problem with scheduler where it "randomly" picks one backup witness and stuck it into a production loop, while everyone else is almost being ignored. It is not dependent on the witness rank (we see witnesses from rank (20-30) to a rare case of rank 100-ish being stuck in a loop, and doesn't pose any security risk.
Good eye for spotting this one!
So it possibly will require another node update after a fix is found?
Yes, but I don't think there will be need to replay the chain (I might be wrong tho). :)
If you want to accompany the development, here is the link.
Unfortunately it seems that the developers haven't seen this yet. The closest I've seen of this issue being discussed in in this post.
They did see, I know a few devs. I talked to them and they are working on it, but I don't have much more information than just that they are working on it.
Nice to know. I don't interact much with people, just read their Gitlab Boards.