Hopefully I might help. I have a CRV with a Blue ox brake which operates the same as Brake Buddy, using an air compressor. I had the same brake lockup condition on several occasions. Once in the middle of a 2 lane busy road going downhill. Had to hold up traffic & go manually release the brake.
I have found 2 things which have solved the problem for me.
First, do not have the seat right up against the brake controller. It needs a little room to flex back after braking. If there is not enough room, the controller jams against the seat & will not release. Not too much, maybe 1/4".
Second, I have found that the brake works just as well at 20-25psi as at 60 psi. I keep my psi as low as possible.
I test my brakes every time we start out on a new run. Every once in a while the brakes will grab but at 25psi its a lot less sudden than at 60psi. After I go back & move the seat back a fraction, I no longer have the problem.
Have been using the brake control for 6 years now. After the 1st 6 months trying different solutions, I find this has virtually eliminated the problem.