Sleep patterns

My 14 month old has slept from about 6.30pm straight for 12 hours since for the past months with 2 naps in the day. Recently, we’ve noticed that although we bed him around the same time, he’ll toss and turn till at least 7.30, sometimes 8. He also fights his pm nap though he’ll still rest for about 45mins-1hr. What’s the take of some mummies out there… skip nap and sleep at usual time to keep routine or nap and sleep later? He also wakes slightly later when he goes down late