My Horse Stops Right After a Jump.

We have been walking/trotting over cavalettis and cantering over ground poles. He has trotted over some small crossrails and did great. I decided he was ready to canter over the crossrails.
I got him at a nice, steady canter and we went over the jump. BAM! Ernie decided to stop. I of course flew over his head. I got back on, and asked my trainer what we did wrong she said as far as she could tell nothing. I tried again (this time squeezing) and he did it again.

Ok that's a different one... usually the problem is slowing down after the jump... Not speeding up (or just continuing to move in Ernie's case).

Sounds like with that type of mulish behavior he would be a good candidate for coon jumping

He stops RIGHT AFTER the jump. He stops dead in his tracks...

Do not go into a two point position but keep your seat more in the saddle, even taking a slightly backward position but you must slip your reins.
This puts you in a far safer position if he does stop after the fence, be ready to use your legs hard to keep him moving forward and your voice and whip if necessary.

Go back to trotting poles and then a small fence and make sure he canters on landing from the fence. Then use canter poles and do the same.

Hi,

This seems like it was a taught behavior. Have you talked to the owner?
Does he do the same on the lunge or free jumping?

You can also put a 2nd jump, a stride after.
When he stops stay calm and ask him (progressively more) to go on after the jump.
This would be a great place to use treats.. Place a barrel or something strait ahead, on which you can put a treat.. he will "very" soon learn that you want him to go on after the jump, or have someone there (even better as the person can move to different places.. once he has done it well a few times at the same place)..
Reward plenty!

Happy Training,