Best answer as chosen by user myzacdog: I think you're right.
Bluetooth sort of came and went with that maker. If the units support USB Keyboards, try ones from Logitech.
Again, because Samsung can't show favoritism they will not publish a list. In my view they should sell a "Samung" keyboard even if it's 199 bucks USD so there is no question about which to use for those that can't try a Logitech.