Issue with Call Group and Direct Routing

nkarp You talk about a "Call Group", but then you mention that the person calling is "hearing the music", which sounds like a Call Queue. Can you clarify which one you are referring to?

If it is a Call Queue, can you check whether the person calling has Call Forwarding enabled? If so, that is likely what is causing the issue. When an agent answers a call, it is actually placing a call from the agent to the caller on the back end. If the caller has Call Forwarding enabled, this call can't go through.

I had the same issue and opened a ticket with Office 365 support about it. After many weeks of back and forth, I was eventually told that this is "working as designed".