I wouldn't use Firefox from Mozilla as they're there to collect your data and grant them permission to use it for processing information you input (such as your history, posts, etc.) The forks are not affected by that, and it's one of the many reasons why so many Firefox users are moving to alternatives.
Are your uBlock Annoyances and AdGuard Annoyances filters enabled? That seems to do the trick for people who are getting the message. I have not gotten it once and I always had them enabled.
When switching to Waterfox, my right click options weren't working. When I moved to Firefox, it worked. Only issue with Librewolf is that there's no mobile variant and I want to keep both my browsers in sync. Even if this risks my information getting used.
On my clunker laptop that I just installed [exclusively] LinuxMint [cininamon version] using the "Firefox" browser, and installed the "uBlock" extension, there has been no problems.