Can't sign even though it's in my devices

[Android Central Question]

Hi, you're basically my last hope.

I decided to update to stock Android 7 on an old phone, everything went fine and on boot it asks me to "verify my Google Account". I sign in with my account, but it tells me it's not an account associated with my phone, and refuse to start. But it *is* linked to my phone, and if I go to "Device activity & security events" on Google I can both see my device listed and that I just signed in to it.

Basically right now Google has locked me out of my phone. Anyone know what to do?