No Longer Works UBUNTU 20.04.6

[abhr0nt]

User-Agent Switcher doesn't work anymore. Any ideas for settings changes I can try?
(Never had this problem before.)

It doesn't work at all. I tried it with all other addons turned off, I deleted all offline content/cookies etc, I even tried turning off/restarting the browser between settings changes and tried other various UA Switcher settings- I allowed it to run in Private Windows- and... nothing. It shows "USER AGENT IS SET" when I click APPLY (CONTAINER) but my cursor over the icon shows my regular, unmasked useragent (as do various WHAT'S MY USERAGENT websites). I tried APPLY (container on window), Refresh Tab, Restart, etc to be complete, but... nothing changes my useragent.

OS: Ubuntu 20.04.6 LTS

Firefox addon, User-Agent Switcher and Manager

FF VERSION: Firefox 123.0 (64-bit) Mozilla Firefox for Ubuntu

SETTINGS:
Allow automatic updates, Default
Run in Private Windows, Allow
Author, Ray
Version, 0.5.0
Last Updated, October 11, 2023
Homepage https://add0n.com/useragent-switcher

[abhr0nt]

• I fixed it. Something changed me to WHITE-LIST MODE, I changed back to CUSTOM MODE (by RIGHT-CLICKING the icon), and- success!

• Question: DO I HAVE TO ADD updated useragents EACH TIME I LAUNCH THE BROWSER?
  I have to do that now. If there's a way to store them somehow somebody please let me know.
• I'm looking over FAQ/tutorials etc and haven't found a way to that yet, if it exists.