Hello MVW I am sorry this is happening to you I have this link I found that will help you stop ad blockers https://support.mozilla.org/en-US/questions/1198516 I hope this helps

Wes

What do the pop-ups say? Have you contacted their support?

Thank you for sharing your Add-ons list. It shows you have this one:

https://addons.mozilla.org/firefox/addon/total-adblock/

I notice on the listing, it says that it has some paid features, so maybe it is nagging you to pay for it? The reviews do mention this behavior.

If you prefer a completely free ad blocker, you could remove that one and check out the following:

https://addons.mozilla.org/firefox/addon/ublock-origin/

You may also want to remove AdBlocker Ultimate and only use uBlock Origin to see if that works for you.