Day nap problems

Brittney • 👪 love my family!
My 4 month old, for a few days now, has been sleeping in his crib during the day.  At night, he sleeps great!! During the day is a different story.  I will put him down for a nap and an hour later he will wake up.  His eyes are still shut but he is screaming as if he is in pain or having a bad dream.  I try and soothe him while in his crib but he just cries.  I will pick him up and pat his back while rocking him and he will calm down and go back to sleep but when I put him back he will cry again.  I'm not sure what is going on. Any suggestions or advice would be great!  FTM needing help!