its been sometime we have been dealing with this issue, but it isn't improving and I hear the same problem from friends who live in the area. (and we don't live out in the boondocks)
We have to go to the front of the house and sometimes outside on the porch to keep the call from dropping.
I have an iphone 7 and my wife has an iphone 12. both phones have this issue. Having WiFi assisted calling helps- but we still have to use the method mentioned above.
I am tempted to change networks but have resisted thus far because of a long relationship with Verizon.
Verizon advertisements claim to be superior.... but we're pretty frustrated.