Potty training

So, my 2 year old is great at javing a pee on the potty. He tells me when he needs go pee and asks me for the potty. However,pooping is whole different story. He gets upset when he needs to poop and starts to run around and hide. But he will not poo unless he has a nappy on. I dont think he’s shy about pooing in front of me because when he a nappy on he will poo any where. In the house I let him run around with no nappy or pants on so he can get excess to the potty quickly.

Tonight, he needed to poo. As we where in the house he didn’t have a nappy on. He started getting upset again and running around and hiding. Almost like he was trying to hold it in. As soon as I put a nappy on him he pooped straight away. Anyone got any advice on how I can handle this? I try to sooth him tell him everything’s okay but it doesn’t help