iPhone 11 Pro calls going straight to VM

My iPhone 11 Pro rarely rings and I end up having multiple voicemails pop up at randomly throughout the day. This is obviously very frustrating.

Do Not Disturb is off. Block Unknown Callers is Off. I now leave my ringer on all day. I do not have Call Forwarding on. I am at home and have good coverage. I’ve lived in the same house for three years and have only started having this problem a few months ago.

I’ve checked all of the things suggested online and nothing has changed. Help!