Could it be that crossing over super admins, who set different states at the same time, caused the problem? Because I was switching between accounts, and I can not really remember the order of actions but, when I did different tries like inline-delete, then unapproval, then moderation queue delete and that from different accounts on different devices (smartphone and desktop), that the database got a hiccup due to wrong record states? I still wonder why it finally worked again...