Thanks for the reply @Viktor_Mudrevsky .
I just have a slight problem here : none of these actually were guest users… These are users who registered, have an email address, and have the Backendless status 1 in the database. That’s ENABLED, right ? That’s how they looked in the database before and that’s how they are in my backup files.
But don’t take my word for it. Let’s look at a specific example, the last one in the list, 0F3270B5-C808-4682-9E18-8D62FC95F6BB. In the backup file provided by @sergey.kuk here, this user also has a bckls__userStatusId of 1. And that was on March 28th. That user got deleted on April 13th, allegedly because he was in guest status. And there’s no way to go back from ENABLED to GUEST. The same goes for user 2964FE93-DF70-4256-8F24-F82BEC356B9B, also with a bckls__userStatusId of 1 in the backup file you provided on March 28th, yet deleted on April 12th.
Forgive me, but I feel like I’m missing a piece of information to fully understand how that could have happened.