I just bought this tab refurbished, and after working initially, the bluetooth did exactly the same as yours. I ordered an ASUS bluetooth usb nubbon, which worked immediately and perfectly until I restarted the computer, at which point, it also disappeared. After removing it and another restart, the original BT options had returned (***). Initially I couldnt get it to connect, but after a few restarts and some fiddling and many attempts, it is now working again. I don't know how or why any of this worked, but it worked for me.