Thunderbird Keeps Asking for Authentication + Cannot Send Emails

 * Server Name: imap.gmail.com
 * Port: 993
 * Connection Security: SSL/TLS
 * Authentication Method: OAuth2

 * Server Name: smpt.gmail.com
 * Port: 465
 * Authentication Method: OAuth2
 * Connection Security SSL/TLS

 * Server Name: outlook.office365.com
 * Port: 993
 * Connection Security: SSL/TLS
 * Authentication Method: OAuth2

 * Server Name: smtp.office365.com
 * Port: 587
 * Authentication Method: OAuth2
 * Connection Security SSL/TLS

Hello, I have been using Thunderbird for years without issue, but three days ago, I started having issues. Now, I don't receive emails when I open Thunderbird. If I delete my password and re-sign in, I receive emails, but cannot send them. Trying to send an email makes Thunderbird ask me to sign in again. I have two email accounts that I use with Thunderbird. Both accounts have this issue. I have this issue regardless of the network I'm in (work, cell hotspot, or home). Things I have tried: * Verified that my IMAP and SMTP settings match the guidance from email servers. * Verified that my computer firewall is not blocking email. * Tried connecting on different networks (so different ISPs) * Deleted and re-entered passwords for each account Here my current server configuration: * Email 1 (@gmail.com) * Server Name: imap.gmail.com * Port: 993 * Connection Security: SSL/TLS * Authentication Method: OAuth2 * Email 1 Outgoing Server: * Server Name: smpt.gmail.com * Port: 465 * Authentication Method: OAuth2 * Connection Security SSL/TLS * Email 2 (@[university].edu) * Server Name: outlook.office365.com * Port: 993 * Connection Security: SSL/TLS * Authentication Method: OAuth2 * Email 2 Outgoing Server: * Server Name: smtp.office365.com * Port: 587 * Authentication Method: OAuth2 * Connection Security SSL/TLS I will greatly appreciate any help you can provide!