I seem to have some trouble once in a while unhitching. I figured it out real soon though, its always the same. Go put it in neutral or sometimes put it in reverse.
The disc that I got with the camper (used) musta been worn out cause it kept falling off when I wanted to back under. Then I managed to fold that one up as I was trying to get under the pin box. I would say the disc is a absolute!
One thing I learned while pulling a trailer behind my motorcycle is to use wax paper on my ball.
The wax paper acts as a lubricant, about like the disc does. A lot better than using grease, the one time I did I managed to get it on pants..... I took a nine state ride pulling the trailer and only changed the wax paper a coupla times.
One trick I learned was the "string"
That makes it a lot eaiser to get the height right when jacking either way. I have mine on a magnet, easier to adjust the string if needed.