>>>>What antivirus is being used? Can you temporarily disable its real-time scanning?
>>>
>>>Fair question. I can ask. It's hard to imagine, though, how antivirus could cause this. To clarify, what happens is:
>>
>>We had a similar issue and the culprit was an antivirus call Morphisec (https://www.morphisec.com/), which is great, but there was some configuration issue. I do not remember the specifics, it was some years ago...
>
>How similar? In this case, an entire record is being copied over a different entire record. To the best of my knowledge, it's only happening in this one table and only occasionally. (But now I think I'll check data from other tables to see if any PKs are out of order.)
>
>Tamar

I asked around. I was wrong. The issue was not similar at all, the problem was that for certain users the data will not be written, but blank records were added. Sorry, I should never trust my memory and always ask first :(