I have recently upgraded my IPhone X’s IOS to 14.5 from 14.2.2 and since then I am having signal loss randomly along with 4G Cellular Data loss. I have tried hard/soft reset, airplane mode on/off, changing to 3G/4G but all results to temporary solution. I try to call someone or send an SMS, but it fails to send/call. Then clears all the signal bars, starts searching for a signal, picks up a signal and then I try again and it works. Then sometime later, I see that signal bars are all cleared again Nd I have no reception. I have tried same SIM Card on Iphone 8 IOS 14.2.2 and no problem.