5 month old

My baby’s naps have been extremely short lately, probably only like 30 minutes. Is this normal? lol. He doesn’t stay awake long either, I don’t want to keep him up too long when I notice him rubbing his eyes, don’t want him to get overtired. He used to nap for 1 - 2 hours just last week lol. Nothing has changed in his room, I’d always swaddle him. Turn on the fan (for sound). Lay him in his crib with his soother & he’d fall asleep.