06 taco overheating after engine shutoff

So I just got back home from the dealership with an 06 Tacoma access cab. Love it. Not as fancy as my 2013 I totalled but it's actually 4x4 instead the dang prerunner. Anyways, I got home turned it off and turned the key into the on position so I could finish the song I was listening to. I noticed the temp gauge climb to about 3/4 and then steadily come back down. Opened the good to see if it was boiling. It wasn't but I could hear a tiny bit of pressure releasing from the rad cap. (Side not the overflow nozzle was broken off the nipple on the radiator when I bought it)
Has anyone had this problem/know how to fix it?

Temp stays steady while driving, I'm paranoid about that needle since my 3vze just blew its head gasket earlier this week so I kept a good eye on it while driving.

Let me know what you think! I guessing it's an easy fix but guessing doesn't work with cars so I'd be eternally grateful if I could get some input.