I have the Charge and live in the Raleigh Area..noticed the same thing this morning when I was out . As I live in an area with no LTE and very spotty 3G service at best..it's hard for me to say if the situation has improved
Its very frustrating when losing the 4G coverage. Are you still experiencing the issue? I would be glad to look into the 4G in NC. Did this start after an application was downloaded? Please remove the battery and reinsert and retest.