Ported number from Verizon to Xfinity but Voicemail still goes to Verizon

I just signed up with xfinity mobile and ported four phone numbers from my old Verizon wireless service. Everything is working great except for voicemail. When I attempt to access voicemail (either by holding the "1", dialing my own number, or dialing *86), I am connected to my old Verizon wireless voicemail. I can't access my xfinity mobile voicemail. There are a few other threads on here about the same problem, but they are closed and they don't specify what was done to fix the problem. Can anyone please help?