I was using Waze a couple days ago while connected to CarPlay, but at a dead stop with the car in Park. The route selection screen on the phone wouldn't let me choose a particular route (HOV route) but it also wouldn't say why. It just either didn't respond to the input or else the route label flashed but didn't actually activate. The CarPlay screen only included the non-HOV versions of the routes, so I just plain couldn't pick the route I wanted.

I unplugged the phone for two seconds, picked the HOV route, and then plugged it back in, but I was infuriated by it.

This is not a knock on CarPlay, but rather Waze's UX decisions. It requires GPS access to function, it can tell if I'm stopped or not.