We believe we have fixed this issue. Try the following:
1) Highlight State of Decay 2 and press the Menu button;
2) Go to "Manage game & addons";
3) Delete all packs from your Xbox;
4) Ensure you download the Doomsday Pack from that menu, not from the Store.
4) Launch State of Decay 2: Juggernaut Edition;
5) Attempt to call in the Ultimate Edition radio calls.
If this does not resolve the issue, please try the following:
1) On a Windows 10 PC, install the Xbox Game Pass app;
2) Install State of Decay 2;
3) Launch State of Decay 2;
4) Load your community and call in a Doomsday Pack radio call;
5) Exit the game and wait about 15 minutes;
6) Return to your Xbox One and load that same community.
Please submit a ticket if it does not resolve the issue.