iPhone 12 Visual Voicemail Not Working Properly

I am in the same boat. I dont even get notifications that I have a voicemail. 

I recently came from verizon and switched to an IPhone as well. 

@ComcastChrisL  Any help would be greatly appreciated. 

Exact same issue. Transferred my line from Verizon to XM with a Google Pixel 3 XL, then activated an iPhone 12 Pro on my XM line and now I don't get Visual Voicemail. I also get weird error code text messages from Verizon whenever I get a voicemail.

Exact same issue here.  Went from  Verizon Android to XM iPhone 12.  I get a notification about an incoming VM which is gibberish starting with VWVMN or something like that.  At least I'm notified, but would really appreciate visual voicemail which I understand is offered by XM.  It sounds like ComcastChrisL helped someone and we would all appreciate similar assistance.  Thank you.

I have the same issue coming over from Verizon

Exact same problem for me. Has anyone had any success getting this fixed?

Here is my suggestion for fixing visual voicemail if you have switched between Android and Apple iOS.

1.) Make sure that the IMEI on your device matches the IMEI on your XM account so that XM knows whether your device is Android or iOS. 

2.) Reset Network Settings. Power Off, then Power On again. 

This probably will not fix the problem for most of you, so you will need to start over as follows:

1.) Call XM at 800-266-2278 and have tier 2 support remove/reset your voicemail

2.) Power off, then Power On again

3.) Now go to Phone > Voicemail and set up your phone (It might say call voicemail)

Here is an old article on iPhone Voicemail https://www.payetteforward.com/iphone-voicemail-use-data-visual-voicemail-explained/

Remember that voicemail uses cellular/carrier data (or WiFi Calling) so you should have your cellular data enabled. 

I also transferred my number from a Verizon Android to an Xfinity iPhone and only receive a VZW text when a voicemail is received.  I just spent another hour of my life on a chat session with an Xfinity representative - they said they "reprovisioned" my voicemail and now it should work.  Instead, it is exactly as it was.  This is very frustrating!  

Try contacting ComcastChrisL

See the earlier post in this thread where he was able to fix the problem for a user

https://forums.xfinity.com/t5/Xfinity-Mobile/New-iPhone-SE-Visual-Voicemail-Not-Available/td-p/33306...

Same with me.  Second level person called me back,  removed the voice mail (although all the old  messages were  still there) , reset it and now it works fine.  I am so thankful for the people on this forum, or else it never would have been solved.

Thanks - I finally had a Tier 2 customer service rep take care of it - kind of following your advice of removing voicemail and then adding it back in - resetting network settings - and voila - I have visual voicemail.  Whew.  Thank you for your advice!