Hey, first time replying to somebody on this website. Lucky you!
Anyways I SOMEHOW managed to fix this for myself magically and it's the most stupid thing yet. IT DOESN'T EVEN INVOLVE THE SOFTWARE. So forget drivers forget anything (Actually maybe don't if anyone has that issue.
For me, the USB 3.0 worked for a long time for me and magically became 2.0 after like a few days ago. Now I decided to play with the cable see if it will tick anything (btw for reference I'm using a KIWI cable) After the 2.0 connected I took out the big one that goes into the computer and back in. Turns out the quest doesn't connect unless the one connected to the computer is plugged in first. After that put in the USB C in the quest and boom. It turned into 3.1 gen 1. It seems the quest has a major software issue and just meddling with the cables connecting sequence seems to tick the 3.0 mode back on.
Look, this probably won't work for everyone but I did this 3 times with amazing success so far. If this works for anyone I will be extremely happy cause this bug is extremely annoying.
PS: When I flipped the USB over too it seemed to connect to the 3.0 mode aswell. So flipping the cable does work and it's more effective, but doing my sequence above makes it so the 3.0 works in it's correct spot if it's a sideway cable.