My 21 month old used to nap from 1130-1 now he’s only doing 45 mins before getting up. Any tips how to get him back to 90 mins? He’s def not ready to drop nap he goes down very easily at half 11 and still shattered when he wakes after 45 mins. Really appreciate the quiet 90 mins I get so hoping this is just a blip? Or is this the new normal? Been about a week or so of short naps. Thanks!