Their is something wrong with the hitch. I had the exact same issue with my 2017 WH 24RKS. The hitch would not un-hook and I could lift my truck off the ground. I found leaving the WDH bars in the hitch worked well as I would crab one and push up and down really hard to work the ball loose.
On my 2018 WH28RL I have the exact same hitch and it unhooks like butter every time.
I actually feel the hitch Jayco uses is superior to most others out there but you can get a bad one too. The one that wouldn’t unhitch gouged the ball in a short period of time. My new 28RL although heavier does not gouge the ball hitch so maybe the unhitching issue is related, not sure.