I’m having the exact same nightmare with Bluetooth too. On iOS 13.x my iPhone X was connecting to all Bluetooth device just fine. The Bluetooth music streaming to my 2016 Infiniti stereo was flawless, connection to my multiple devices (MK Smartwatch, dashcam, etc.) were all fine. when I updated to iOS 14.x this call changed. Now it won’t connect to the stereo without me turning Bluetooth off and on, then selecting the car manually as quickly as possible. Connections to other devices drop if the phone isn’t mere inches away from it. if my phone is in my right-hand jacket pocket and my watch on my left wrist, it drops connection. I have tried factory resets of all devices and the phone, but nothing works. im seriously considering the real solution to be a move away from apple if I want some consistency.