LTE Service Issues

My i phone 7 has service sometimes but other times it does not. It will say “searching” or “ no service.” I can still use my phone on wifi but thats it. I thought it had to do with Verizon, but my wife’s phone works just fine. I also thought it was that I needed to install the latest update but that only helped for a few days and I'm not sure that was even the issue.

Should I call apple or Verizon? The phone works great when i have service so id rather just get this one fixed.