I'm having the same issue, I noticed it this evening. I tried uninstalling and re-installing the browser extension. However, just like silentjim posted, I have it so the extension shows "Prevent tracking on all websites" is checked ON. However, all the ad-trackers as "allowed". Nothing I click on will cause them to be "blocked".
I have the most current version of Firefox (version 101.0 64-bit), and the browser extension is version 22.4.144, last updated June 3rd, 2022.
Please help.
EDIT: I have the most current version of Avast Free: version 22.5.6015, build 22.5.7263.726.
I also noticed, when I go to Browser Extensions from the Avast Antivirus interface, when I go to click to Enable the extension for Firefox, it doesn't get enabled, and it just goes to a blank page.
EDIT #2: When I go to opt out from all new advertisers, it seems to be taking a long time to finish. It is saying "Opting out in progress", and a circle keeps spinning next to where it says that.