bluetooth ios14.4.2
Seems my iPhone 12 Pro can’t pair with BMW connected drive after update 14.4.2
Before updating to the latest iOS 14.4.2 as told in your post what was your earlier iOS version. Then you can look into the iOS changes that have happened between the earlier version on your iPhone and this new version that you have updated now.
This will give you a broader idea of the issue if it is directly linked to the iOS version or is triggered by something else.