"The Subscriber You Are Trying to Reach is Currently Not Reachable" Message Plays on Voicemail When Phone is Off

Alex

Symptoms

While the phone is off, incoming calls to the phone will receive the following message, "The subscriber you are trying to reach is currently not reachable. Please try again later."
The message will loop until the call timer reaches 30 seconds, then the call will route to voicemail normally