When I get a missed call the phone does not show a notification on the lock screen at all, no matter how many calls.
Notifications only appear after I unlock the phone.
They start working after I restart the phone but stop working after a short while, maybe half an hour or so.
I did not have this problem with Oreo. This is unacceptable. I have the latest November update installed. The exact model is TA-1043 with firmware 00WW_3_260_SP01.