Hi porthole,
When you are unhitching, you might want to drop your hydraulic or electric front jacks about halfway, pull the pin on your jacks to drop the legs (I always have a
4" x 10" x 18" long piece of wood under each jack), put some reasonable weight on them, enough to lift the truck slightly, then pull the handle to unhitch. This comes straight from a Pullrite technician. Once you pull the handle successfully, then raise the trailer until u see the ramp saddle separate slightly, then pull your truck forward. once you remove the 7 way electric cord, and emergency brake switch or you may be sorry LOL. Just me and the Pullrite technician's 2 cents. I have done this about 100 times. It's sometime very difficult to pull the hitch handle if you don't place weight on the front jacks. If you still have trouble, making sure your emergency brakes and trailer brakes are on, put the truck in neutral, and rock. Sometimes that releases the pressure against the hitch from the pin cushion.
If you have an auto slider, don't forget to spray slip plate dry graphite on the top and inner part of the slide and use white lithium grease on the pin cushion neck and the saddle ramp.