I am having issues too. I live in England and after the update to IOS14 the signal is pretty bad. I have been missing calls like mad. I also have a work phone which is an Apple iPhone XR and my phone is iPhone 11 Max Pro. At the start, i thought it was signal coverage with my network provider but checked a few times and signal is great. My daughter is also having issues after the update, she also has iPhone 11 Max Pro. I hope Apple can resolve this issue quickly as i am a manager to a team of 12 and working from home until further notice. This is making communication with the team very hard. I've lost count of how many times i have had to turn the phone off and on, place it on airplane mode etc...