I don’t use the optimize feature. I tried it once and it pretty much set everything to low. I have a 3080 and nvidia thinks I should run low settings? I mean, my CPU is old, but I can run much better settings than low! But the optimize feature selectable and I just leave that alone. No problem.
I’ve use geforce experience updating for years without an major issues I recall. This is a recent thing. I seems to have started with one of the recent MSFS updates. Not immediately after, but I think it was one of the small updates after WU4 France. No other game or sim I’ve tried (admittedly not many) is dramatically slower, juse MSFS. But reinstalling the driver with a clean install fixed my problem? But not if I use geforce experience? None of that makes much sense. But with this software, any strange thing can happen it seems.