Unable to link Gmail with Thunderbird on Linux as Authentication fails.

I already have Gmail linked to Thunderbird on Windows but now have a Linux computer. When adding Gmail, I am taken to Google's website as expected which grants authorization after satisfactorily logging in. I'm sent back to Thunderbird that then displays Authentication failure. There seems to be no way around this despite looking for any Google credentials in saved passwords. Thunderbird has added other mail accounts with no problem. Google will show that my Linux computer is linked but Thunderbird rejects any attempt to sync with Gmail. I'm wondering if there remains any Google data within T'bird that is corrupted that needs to be cleaned out to start over fresh.