This is an update on my situation. I have an iPhone 15 ProMax and a Pioneer DMH-4660NEX receiver. I had been able to connect Carplay to the Pioneer receiver, but the navigation apps did not work well (bad directions, unnecessary turn, inaccurate locations etc). After talking to Pioneer and Apple, each blamed the other and had no solutions. I finally figured out that the 3d calibration setting on the receiver had to be reset. This is not mentioned in any of the Pioneer literature. I found this advice on a random blog post. Now the navigation works fine, both on Waze and Apple Maps. What a relief!
Now the issue I have is a smaller one. The phone will connect Apple carplay every time with an Apple cable to the receiver. It will connect sometimes wirelessly but not always. I have reset all the Bluetooth setting and WiFi setting many times and the problem still persists. I can' figure it out. One odd thing I have noticed is that the Pioneer has two different Bluetooth channels that show up on my phone. Sometimes one works and other time, the second one works. Anybody noticed this or have any idea why one receiver would broadcast two different Bluetooth channels? Thanks, Brian