Sporadically missed texts/calls + "Not registered in network" + Terrible Support = Severe Problems

Please Help!  Why would an incoming call at 3:15 am on a particular date in September 2023 NOT appear on my call/activity log for that date?  There is no question that this call was received on the date/time in question, as I personally received the incoming call that lasted only approximately 10 seconds.  I was in an industrial area, only about 1-2 miles away from the Caller, also a T-Mobile customer, and do not know if the Caller "blocked" their number or not.  Can anybody please help me understand what possible reasons could exist that would show this as a nonexistent call on my activity/usage records?  Any ideas on where else to find proof that this call was made or received?  It also does not show up on my "recent calls" phone list on my iPhone itself.  I don't recall if I may have deleted the "incoming" call from my iPhone device itself, by swiping left.  I need to find proof that the call was made/received.  ¡Gracias de antemano!