This is more of a solution then an actual "FIX" simply hold the power button and the ... button on the bottom right of the steam deck until you hear the menu start up sound and let go and it will boot up into the SteamOS menuand from their you will factory reset your steam deck to factory settings, doing this will erase all user installed data on the decks SSD, all data on the SD card if you have one will not be removed. This is most likely a bug with the unstable version of the OS.