Authentication error with centurylink.net email

Really weird problem with a friends thunderbird setup. All of a sudden my friend was unable to get here emails. It kept saying the password was incorrect. Of course she didn't know her password but it was saved in Fire fox. Found the password and verified her centurytel webmail works. So put it in Thunderbird and still give me an error. I then decided to install Thunderbird on my personal laptop and everything works fine. So I decide to do a clean install, deleted all profile folders and everything. Reinstall Thunder bird and get an "Authentication error". I tried disable all her firewalls on her computer (Windows 11) and disabling the firewalls on the router/modem itself. It still doesn't work. I think next thing I will try is my laptop that has thunderbird installed with her email account. Any other ideas?