The same thing happens fairly often in my new Denali. I'd say it happens maybe 10% of the time.
Another annoying thing that happens fairly often is that CarPlay just outright doesn't even connect to my iPhone, wired or wireless. At first I thought it might be my phone specifically, but then I tried connecting CarPlay to my work iPhone and my wife's iPhone and both had the same result. To fix the issue I'd have to shut the vehicle off and exit the vehicle so the screen would turn off. Then after a minute get back into the vehicle and power everything back up, CarPlay connects again just fine. I noticed if I stay in the driver seat and just open and close the door to get the screen to turn off, it doesn't resolve the issue, maybe because the key fob is still recognized as in the vehicle and it doesn't shut everything down completely. Looks like the infotainment system runs off a Linux based operating system so I'm hoping the software bugs can be worked out pretty easily with a simple update.
I've made my complaints about it in a couple surveys, but not sure how often GM actually pays any attention to the details or comments that their customers leave in surveys, or how they prioritize the issues brought up.