Hello @Charles Abi Khirs, thanks for your reply! Answers to your more questions in line below, let me know if you think I can narrow it down any further.
1. What D365 version are uou using? Online 9.2.21055.00137. Dynamics 365 CE Online.
2. What is the recurrence of this update? 128 on May 25th, 716 records were deactivated on May 13th, and 84 on Jun 10th. I haven't been able to identify a pattern yet. Perhaps something else is triggering it, or someone was doing something manually before.
4. Does this update is applied to all records? Or specific ones? Just one entity, for specific records, no pattern I can find as to which records vs others.
3. What data are being updated? Or it is only being desactivated? Just being deactivated.
5. Is there any process/batch that is being executed and do the update? I don't know. I can't find one that would, and there are no system jobs that say so, however most of the workflows are deleting system jobs after they succeed.
6. Do you have a power automate that might be scheduled to run and do the update? Nope.