1. Verify if your router or router software that you installed in your PC is doing something fishy.
2. As long as you have a browser window with cookies - even new IP address should NOT matter. It should allow you. I am almost always working in cafes with different IPs it - just works.
3. Please please verify your recovery email ID. Some times I have made the mistake of typing first.last@ instead of without dots. Send an email to your recovery ID to test.
Please get a 2FA U2F token.