Would you be amenable to telling us what it was, out of curiosity?
As you can imagine there’s a count used by the pagination which would sometimes not represent the proper count. You might think that was because of some deletions not updating the count but that is not obviously the case. In fact there could be many weird and wonderful reasons for the count being off. The relatively straightforward solution is to not worry too much about the primary cause of the miscount right now, but just to make sure the number is correct. It doesn’t remove the glitch, and you may occasionally spot an occasion where the count is off for some reason and the pagination goes weird, but the count will get regularly checked and updated and the problems will not persist as they did.