Hi, welcome to YT. I may not be much help but have you tried an ex pen with potty pads? You could put his crate in the ex-pen and then he could get out of the crate to do his business on the potty pad. This is the only solution I can think of. I hope someone comes along that knows more about this problem because I've never heard of a dog doing this. Best of luck, and I sure hope you don't have to rehome him because of his problem.
