My 2 year old (26 months) loves the potty but has trouble pooping. Help!

Hi - my 2 year was showing major signs of being ready to start potty training. We bit the bullet last weekend and did it an he caught on really quickly (he was already using the potty a lot when we would). However, the pooping is really difficult for him. He’s a regular pooper and sometimes even twice a day. However, he will not poop on the potty until it’s dire. Over the last week he’s only pooped 3 times and it takes days of working up to it. He will dance around saying poop and holding his butt but will not sit on the potty to poop. He won’t poop in his pull up either (we use pull ups for bed and nap).

He’s now started waking up at 2:30 or 3:30 whaling for us and will not go back to sleep. He’ll just do this dance of needing to poop and won’t go.

I’m thinking we may need to pause and go back to diapers for a bit but I don’t want to confuse him.

Any tips?