18 month old waking too early. HELP!

Hello all. I’m desperate for help. My son is a 18 months old and has recently started waking between 430 and 445. He wakes up and immediately stands up in his cribs and waits for us to get him. After about 15 minutes he starts fussing. He is a very very stubborn child. If I go in there to try to lay him back down he freaks out harder.

We put him down at 7pm. I don’t think he needs to go down early because I can tell he is still tired when he wakes up in the morning and he is a disaster in the evening because he is so tired.

He does one 1.5-2 hour nap at daycare. I need help!!! I have a new baby on the way in a few months so I need at least one of them to sleep for me ??

Advice? Experiences? Pleeeeeease!!!!