Do you use ground poles? Also maybe try some canter or trot poles!
Try putting poles on angles like put Half of the pole on the standard and leave the other side on the ground and put the rest the opposite way of each ot
grids are always good for learning how to use there body or using trot/canter poles before and after a jump, i recommend about 10-11 foot steps between jump and pole😊
Pole work, and lift his hind legs leg towards his stomach, another is make him put his head in between his front legs with a treat (not recommended with a halter on for the last one)