It’d always format, then tell me “Format Error: The SD card formatted correctly, however it failed to mount while the system was running”, so I restarted it… Nothing. I tried a LOT of stuff, and decided to format it myself and manually tell Steam to make a library on it- it worked! However the SD card is still refusing to mount in Gaming Mode.
i have the same issue on steamos 3.5.1 beta.
for some reason the issue doesnt appear in 3.4.
I already contacted steam support. At the moment, they have no idea and i need to do a lot of shizzle for them on the steamdeck of mine to troubleshoot…shit.