Hello, we found out that the reason for this is the iPhone 12 simulators have a Watch paired by default in them. If you look at Simulator lists and select your iPhone 12 (Pro and Pro Max), you will see that a Watch is paired with it. So when you use these simulators, it also builds your watch app scheme, if you have any. So you either delete the watch app from the simulators or keep it and add it in your other simulators making sure that anyone who works with you does the same thing so it doesn't keep on changing. Hope this help you out!