OP, are you using a Teflon lube plate on the BD3? Trailer Saver warns that some are too thick.
Has anyone modified the pin on the trailer?
The trailer plate should set on the fifth wheel plate in the truck and you should be able to look in the rear of the hitch and see the jaws completely enclosing the pin.
Are you using the procedure as prescribed by Trailer Saver for hitching? You need to have the trailer pin slightly and plate slightly lower than the plate on the hitch. When you push back into the trailer, the pin will ride up over the hitch and latch into place.
The lever on the hitch head needs to be slightly forward at the 10 o'clock position when unhitching. When hitching, the lever should be at 9 o'clock position. When you lock into the latched position, the lever will snap back to the 8 o'clock position and the red indicator line will disappear.
Ken