UPDATE!
Well I rode dear old Murphy today keeping everything that has been mentioned on here in mind.It was a shocking improvement.
We rode on a moderately loose rein pretty much the hole time and I consciously made an effort not to pinch with my knees/thighs and he was fantastic! There were no sticky spots, he threw no tantrums, and he even “jumped” into the canter instead of falling into it. I tried to keep it exciting and put up a course of poles and did lots of loops and circles and transitions to keep him on his toes.
Thanks, you guys, for helping me realize what I was doing wrong! This is only one day of this effort, but hopefully it leads to more!