Last time, I had a similar issue with Oneplus 2, I troubleshooted the problem with OnePlus 2-level tech support (nicely organized by Amazon) and they decided after 3rd try that nothing to be done possible. Google said last time that the problem is OnePlus, because not pure Android. I have now troubleshooted the problem with 1-level Oneplus tech support, but they cannot diagnose the problem enough, but they note that it is not possible to setup the phone with 2-step verification at all.
I cannot disable the 2-step verification because of security reasons. The phone does not accept my password to my Gmail account, neither accept app specific passwords. I repeated the steps now at least 50 times now. I can login into pure Android phone with my login details at the moment: Samsung Galaxy S8.
I suspect that there is something corrupted in the hardware. Initially, the problem in the phone was that the sound was broken: crumbless, regardless if you use loudspeaker or headsets. So oneplus tech support decided to change the motherboard. Now, the motherboard is new but I cannot anymore login to the phone.
I think to get the warranty is the only way to go or have 2-level tech support troubleshoot the phone.
Waiting 15 minutes, I get the screen
Something went wrong
Sorry, something went wrong there. Try again.
Then, pressing "next", it gives the login screen again where you have to put your email address again. I do it and give the password. It goes back to the loop where it says the password is wrong, although is not wrong.
The 1-level tech support decides to do the second motherboard switch. I am waiting for it and then troubleshooting.
Phone: OnePlus 6T
OS: the newest 10.10.2019 version