Why my boy is struggling with naps?

Hello beautiful ladies there. My 7.5 months old boy has been struggling hard to fall asleep while nap. He will cry out like anything before he can fall asleep. I see all the cues that he wants to sleep but the moment we put him for nap he will start crying. He sleeps very well in the night. Always sleeps on his own. I don't know what to do?

I am wondering if this is an issue with many babies around this age. Just started little ones program. Sleeping and feeding guide. Hope it helps us!!