Apple Watch 7 Voicemail drops off watch phone app

I have an Apple Watch 7 GPS + Cellular and iPhone12 Pro on Verizon. All OS are up to date. If I restart my phone, the Voicemail button disappears from the Watch phone app. If I remove the SIM card and replace it, the button immediately re-appears and will remain there and operational until the phone is restarted again. Then it is gone again. I have tried "re-pairing" the watch and getting a new SIM card from VZ. Any ideas?