Same behavior - deleted StorefrontAuth-yadayada, also moved a folder called AmazonAuth there just in case.
It asks for username, password, 2FA, then doesn't log in.
If I log in manually it saves the login username, and returns the logged in page, but still doesn't complete the process.
You can see it is logged in my account. Attempting to rerun the process returns the logged in page after that.