T-mobile techs clueless about Google blocking devices that are not certified by Google.

It's o.k. there's an option for de-selecting 'require certification' in your phone's 'google account' section, on the security tab. I bring my own phone, rooted from Vietnam (computer nerd) So mine rarely ever pass valid certification. - also, if on standard or flagship phones, unselect auto daylight savings time, and dial your date back a year. Save, exit, restart phone, and then undo it.. I know, it sounds stupid. The date can hang up, and make the phone think the certificates won't be valid for 10yrs/100yrs, etc. I wouldn't mention it if I hadn't gotten a few repairs that were just a disoriented device. 🤷🏻