Yeah I know, first commandment of upgrades:
Thou shalt never upgrade to any version xxx.0
Mea culpa. But I fell for it earlier today and now Firefox works for no more than a few minutes before the cursor changes to an ouroboros then, after a while, Windows says ‘Firefox is not responding’ and I have to shut it down.
I’m still using my Win10 desktop.
There are references on Reddit to this from other people, so it’s not just me, and some suggest it can happen under Win11 too.
I’d recommend resisting the upgrade until they’ve managed to build a reliable one.