Xfinity Mobile "Voicemail not available"

Purchased a new Samsung Galaxy Ultra 24 from Samsung, came early, changed the sim card to the new phone from the Samsung S23 Ultra.  setup the phone, items seemed to work correctly.  All Voicemail stopped, called Xfinity spent an hour on the phone, he got it working for about a day or so, stopped working again, more tech support time on the phone for 1.5 hours, couldn't get it to work, said they are working on it and should be done in 48-72 hours, nothing at this time after 48 hours.  I need to get the voicemail, the Xfinity web account called the S24 Ultra a Moto E5, others have reported the same thing, this is an unlocked, brand new from Samsung S24 Ultra, this is real mess, I need to have the voicemail option back and working again.  Both phones were running Android 14.0, the S24 Ultra was running the new 6.1 UI though instead of 6.0, that could be the issue??