Is this popup on the bottom right corner each time?

It could perhaps be push notifications from some certain sites. https://support.mozilla.org/en-US/kb/push-notifications-firefox

You can do a malware scan just to be sure.

• https://support.mozilla.org/en-US/kb/troubleshoot-firefox-issues-caused-malware

Does it mention some website in this pop-up? You can type about:serviceworkers in the address bar and check if you have a service worker you do not recognize.

Thanks for the suggestions. The pop-ups are in the lower right corner. I click to close them and they pop back up. I did click on one but it did not take me to a website. It didn't do anything. Because it did not go to a website the push notification doesn't have anything listed.

I did run a full scan on McAfee and it does not find any viruses. I also went into my control panel to see if there are any new apps/programs that downloaded in the past week (or longer) and nothing unusual there. ‎I went to File Explorer and click on Properties for Mozilla app and it has "created Thursday, ‎November ‎30, ‎2023, ‏‎1:25:29 PM" I'm not sure if that is when the update happened or?

I cleared my browser history for the past week, cleared cache and cookies. It has not popped up since yesterday afternoon and so far today. Maybe that fixed it???????????????????

The "Thursday, ‎November ‎30, ‎2023, ‏‎1:25:29 PM" is the date and time that the update took place.