Help for child waking up 20 minutes into napping

[Fun&care]

I would put him in a separate room with a sound machine, say goodnight, close the door and don't come back in to shush him, pick him up, nothing. I've had more than one dck wake up 30-40 mins into their nap and if I start going in even just to shush or say go to sleep, they quickly get used to this interaction even if it is minimal and will wake up every time a sleep cycle ends (about every 40 minutes) and NEED that interaction to go back to sleep. Of course you should check on him just don't let him see you. He might really scream at first when you don't come but give it a few days and I promise you should see improvement. I know issues like this are frustrating...good luck!