Baby all the sudden won't nap in crib?

My baby has been napping in his crib for three months. All the sudden he won't nap anywhere else except on me. We started sleep night training and ever since we started that, he won't nap unless held. Everytime I go to transfer him he is wide awake. Even being held he is constantly moving. It's as if he won't fall into a deep sleep anymore. I

Is anyone else's Lo doing this? Could It be sleep training or leap 5? Could he be getting too much sleep or ready to drop a nap so he can't fall into a deeper sleep?