Meta (facebook, insta, etc) puts code in their web pages that prevents you from browsing away from their sites after landing on their page. As far as I am concerned, this is malicious as it prevents 'free use' of the internet, trying to force me to stay on their site. I refuse to use ANY Meta products, but occasionally land on one of their pages as part of search results.
Is there anything Mozilla can do to block this malicious script from executing while still allowing me to land on the page?
Is this a problem where additional entries are added to the back button history? You can right-click the button to look at the list of what you can go back to.
If the back button is gray -- there is no back button history -- is it possible that the site opened in a new tab? If you use the Facebook Container add-on, it's normal for links to Meta sites to open in a new tab, that's part of how the isolation works. Unfortunately, sometimes the original tab is closed and you need to reopen it using one of these:
Here is a better description of the steps (see screenshots)..: