Originally Posted by JakeT85
I used the toolkit and relocked the bootloader, went back to s-on. The phone still says tampered and relocked in the bootloader. The problem I'm running into is, I want to return the phone to AT&T store. I have clicked to reset the device from settings, as well as from the bootloader and the phone does not restore it just boots into teh bootloader showing tampered and relocked. I think this is because the know the AT&T rep will restore it and see it. Anyone know of a way to fix this?
Sounds like you didn't flash the stock recovery.
There is a guide on how to lock your boot loader without it saying relocked in the m8 forums.
You would need to soff, unlock boot loader, flash stock rom and recovery, boot into twrp "don't flash recovery" and root your phone, relock phone the proper way, remove tampered label, go back to s-on, use supersu to remove root, then factory restore.