Visual voice Mail problem iPhone 11

XM customer since 2018! And I have always had visual voice Mail on android phones. Recently bought iPhone 11pro max through XM then visual voice gone! I’ve been at this for 2 months. And I’ve tried everything. Many people seem to have this problem when they switched from Android to iPhone. Apparently some XM agents have been helping some customers to reset their voice Mail and that fixed the problem! If anyone has a solution please share! I am hoping to get the “right XM agent” through this forum! Please help!!!!