Same. And not only with Google, but also with Microsoft AND when getting to make adjustments to my account on Opera either.
Tried to download a different Opera browser bc of these issues & in order to login, password goes through but it doesn't take any backup codes & I don't have it attached to an authenticator, so it doesn't let me login. But I can't generate different backup codes or disconnect the one- time authenticator thingy due to not being able to receieve it, so either way it keeps me locked out like a Catch-22.
Very frustrating since my entire online life is intertwined through Opera - Google- Microsoft.
OH! What's more random about this bug is if I need to login using a backup code in anything else, it accepts it, but through these portals it claims invalid.