iOS 14 incoming call issues

I'm having two problems with incoming calls:

1) Some calls only briefly show on screen and then stop. The phone barely starts ringing. Sometimes the incoming call shows up and stops repeatedly for 5 or 6 seconds. The call log shows, in one case, 13 incoming calls - which were really just one. While all this is going on I can't answer the call. I have now missed two important calls because of this (I don't always see the phone to know there's a call trying to come in.)

2) Some calls, behaving otherwise normally, only show the option to answer, but not the red decline option. Both options show on my watch.