Happened to me too. The thing that triggered lockout was attempt to login from different country (I've changed my VPN provider). I didn't give Google my phone n

Happened to me too. The thing that triggered lockout was attempt to login from different country (I've changed my VPN provider). I didn't give Google my phone number so the only option left for recovery was tricky questions like "what city you've been logging in from" which I failed to answer.