Are you on 1.0.8.1.00 ? That’s the last for non DPAF available. That’s indeed strange if you can’t assign them. I did notice when I tried to assign button 1 vs button 2, it had less options… so maybe look at that… for my firmware 2.0.9.1 (DPAF) ive ...
You can assign them to the number pad on the back of the camera. In the menu there’s an option in the drop down list for something called user assigned or similar. I did this when I had it on a gimbal.
