Question [Q] Phone goes back to a restore point after reboot.

I got this htc ONE form a fried of mine and all the normal functions are working, but I cannot make any changes to the memory or anything stored in the phone, even if I do a factroy reset, after rebooting it goes back to the same restore point. all the data will be same i cannot make change at all. I have tride to fast a differnt recovery and ROM, the don't work either. I'm not sure what has happend, bootloder is unlocked in this phone and is shows tampered flag alos,
any advice will be highly appriciated,
Thank you.