M.C.
Hi
My son did the same thing. He was around the same age, we were also not potty training especially since we had a new baby to take care of. He was so regular every day after breakfast than it changed to after dinner but still during our wake time. Than one day out of the blue he started pooping during his sleep either when he went down for the night or during naps. We were puzzled but we just let it be and it stopped altogether. I think the pooping in the sleep lasted about 6 weeks to 2 months. We always lathered some lanolin or rash cream before he went down for bed to prevent any rashes. We also checked on him while he was asleep to make sure he isn't sleeping in a poop diaper. It does go away thankfully. We never forced the potty on him. He did not want to sit on the potty not even at daycare when all his friends were doing so. Than one day out of the blue he announced he wanted to sit on the potty. So we put him on and he was done. The next time he asked to go on the potty we were with his cousin of the same age and they both had their first potty experience together. He's been pretty good on the potty at home than a few weeks ago it stopped. But in day care he's in underwear and he had few accidents if any; but at home he only wants a diaper on like his infant brother. When in Rome, do as the Romans do. I'll just wait patiently until he is ready again.
Hope this helps