iPhone 12 Pro Max Bluetooth issues

So I have an iPhone 12 Pro Max on AT&T. I owned AirPod Pros, and a Series 6 Apple Watch. These devices do not reliably stay connected at home or away.

I also drive a Tesla and use my phone as the key - the iPhone does not connect to the phone, at all even when I try to tell it to connect.

I own an electric skateboard called a OneWheel that is controlled by Bluetooth. The iPhone 12 Pro max does not reliably connect to that device, or will randomly disconnect in the middle of a ride.

I have reset every setting on this phone, I have completely wiped the phone and started fresh with no apps. I tried each app independent of the other and still nothing.

I have replaced this phone under warranty and gotten a new iPhone 12 Pro Max and I still have the same experience.

I have an older Pixel 3 XL that works just fine with all of my devices, but I am paying for this phone and would like it to function.

Has anyone else run into this? Any suggestions or thoughts?

Thanks