Application Fails in some Locations – AT&T Navigator: Maps & Traffic Review

Long time user who is recently finding the application malfunctions in some areas. To troubleshoot AT&T sent me to Apple who in turn say it's an AT&T issue. What happens is voice navigation quits working. Choosing to adjust volume fails as only ringer volume is active. The location icon seemingly cannot determine the direction I'm going. Happened first in Savannah, GA and then in Gainesville, FL. And it's a repeating problem in those areas. Happened again today as I drove to St. Simons Island, GA. At the same time Google maps worked fine. It seems there is some sort of interference causing the app to fail in some areas.
Review by JAX062583 on AT&T Navigator: Maps & Traffic.