Can definitely attest to this. Librewolf is my daily and I run it pretty aggressively (uBO options/lists, strict blocking DNS, etc) and sometimes I'm left scratching my head where things break. Recently had an aha-moment that felt triumphant when disabling the limit cross-origin referers, as silly as it sounds. Alas, I guess I prefer it this way.
I use IronFox and LibreWolf as my daily drivers, but I keep Firefox installed alongside them for the inevitable site that just doesn't behave correctly. Not unlike having to reach for the big blue "E" in the bad old days.