Your pup is not rebelling, and I doubt if he has a behavioral problem, though only the experts would know for sure.
I know when my girls are going to poop. They almost always poop first thing in the morning, either before or directly after breakfast. Then sometimes they will go in the middle of the afternoon around 2pm. They don't always go at night, hence the first thing in the morning poo.
If I take them out at their regular time, and they do not poo, then I put a leash on them and keep them with me because I know if they wander off, I am going to clean up a pile somewhere in the house.
I think you need to keep a little chart of what time your pup is pooing for about a week, and then make sure you have him OUTSIDE at that time. Try it! I hope it works for you!
