Perfect, you are the best! . I have deleted a item and now it works.
But, i have checked register with blocked emails after the mail list import few months ago. At that time it worked. Is there a problem with the cache? Maybe this is not updated regularly? I will take the point in my regular checks.
No, generally I would say that is working as I would expect it to
Looking at the code briefly, there may be a situation where if you previously had 0 banned emails, and then inserted some new ones directly, that the first time a banned email is checked for after that, it may have done an initial rebuild of the cache, but beyond that only deletes and inserts would trigger a rebuild under those circumstances.
From here on out I would just assume that you have to rebuild the cache manually if you ever insert any records manually.