I have tried everything I could think of, formatting the card, installing a game without it, removing it, restarting and then inserting it.
No matter what I try, the deck keeps setting it as the default drive.
I’m on stable release, latest update. Happens on both new OLED model and LCD.
The problem with the SD card seems to affect all models of decks, not just the oled.
I also had very slow internet speed at the beginning (around 5Mb/s) but it went away after an hour and a restart. If you still have problems, try a factory reset in the system settings.