Thunderbird for Android doesn't support the use of oAuth 2.0 with Pop connections. I suspect your desktop accounts are setup with this configuration and imported by QR code into the mobile app. This would explain the error you see.

If this is the case, you have two options.

1. Continue using oAuth 2.0 authentication. You must change from Pop3 to an Imap connection.
2. Continue using a Pop connection. You must ..

a. Generate an app password via your providers webmail settings. b. Change authentication type in TBA accounts from oAuth 2.0 to normal user name & password. c. Enter the newly generated app password in the password field.

Note: App passwords are a generated 16 digit passcode, not your normal email account password.

To check if Imap or pop is being used ... Navigate to settings > account name > fetching mail > incoming server.

Pop Server name = pop.gmail.com Port = 995

Imap Server name = imap.gmail.com Port = 993

Imap is the modern connection protocol, supporting sync on multiple devices.

Thank you for your response. I apologize for taking so long to get back. I ended up uninstalling Thunderbird and then reinstalling it and NOT syncing with my desktop, but just adding the accounts individually using my Google password, and it is working now. Your response did set me on the right track for pop and imap. Thanks again!