Why my users automatically get deleted after 7 days?

Good morning!

I see from my user account history, there were 2 users had been automatically been deleted consecutively in 2 days around the same time at night.

I did not install any plugins that allows all users automatically get deleted after 7 days, but I encounter this problem. I’m very nervous now, because there will be upcoming users get deleted tonight when times up.

I’m not sure which plugins in my website have this unwanted function – which I call it a bug. I do not know how to troubleshoot to find the code, I can’t troubleshoot by disable all plugin and enable them one by one, because the upcoming user will get deleted is in the night. Anyone could help, please?