Xfinity Home Voicemail, access from Any Phone not working with Cell Phone

I can access my Xfinity Home Voicemail from my Home phone with the *99 feature.

When I try to use my Xfinity S22 Ultra or S9 cell phones, as instructed,

1. Dial your home phone number.  2. When your personal greeting starts, press #.

Doing so with the cell phone, pressing the # key generates the tone, Home Voicemail will not respond to # tone.  Cannot hear voicemail.

Voicemail Login is Off.

Is there something I'm missing?