I've had this problem since switching to Verizon prepaid in November 2018, but it has gotten worse in the past few weeks.
When I receive an incoming call, all seems to work as normal; the phone rings, the caller id comes up on the screen, I slide up to answer, and the screen changes and starts to count the call time as if I am connected. But I hear nothing on my end and the caller just continues to hear ringing. In fact, on the caller's end it just keeps ringing and ringing and never goes to my voicemail. On my end if I don't hear anything, I can hang up and try to call someone else, but my phone won't place the call until the person that was initially calling me has hung up. In simple terms, my phone acts like it answered the call, but apparently the connection did not happen.
This happens sporadically and I have been unable to find a pattern for when it does occur. It is different callers (some cell phones, some landlines), it happens at different times of the day and in different locations. I usually have at least four bars of service when it happens, so the connection with Verizon is strong.
I have already tried the following:
None of these changes fixed the problem.
I have a Moto G6 Play with prepaid service. (Although I see a few other forum posts from people with this exact problem but different phones; none of which seem to have been resolved.)
For me, either turning on/off Airplane mode or reseting network settings will correct the issue for a while (maybe a week).
I have been having the same issue for about a year with my iPhone 6s which I just replaced with an iPhone 11 including a new SIM card. I'm on the smallest Prepaid plan. I was hoping that the new phone would do the trick but no. I believe the issue is with the network. I heard that the final step is to ask the "carrier to reprovision your account" but haven't found a way to do that yet...