This started happening to me 1 week ago. 2022 Toyota Rav4 XSE Hybrid, wired CarPlay, though I was using a bluetooth adapter for wireless CarPlay at the time. iPhone 16 Pro, iOS 18.2.1, though I was already running this when CarPlay went kaput.
I drove the car to a store using CarPlay and Google Maps just fine, turned off the car for about 5 minutes, and ever since then, no CarPlay.
I've removed the bluetooth adapter, tried many different USB cables directly, and nothing. My phone charges over USB no problem. I've tried all of the troubleshooting tips I can find, both on the iPhone and Toyota's infotainment system. Yes, I have turned it off an on again.
My system is up to date according to the firmware page @GreenEagle posted, if you can call 2021 up to date.
It's driving me bonkers, especially since I don't believe I've seen a single actual solution on the web. I didn't realize how much I rely on CarPlay until it stopped working.