The EVO LTE is a turd when it comes to anything to do with its signal. I wish I could go back to November 2012 and change my EVO LTE to the S3. I have really good 4G in my area but not on my EVO. I'm lucky to get 3G. This is definitely my last HTC phone and probably last run with Sprint over this crap. Good luck getting them involved. Don't get your hopes set too high.
HTC Evo 4G LTE (s-off)
Samsung Galaxy Note II (rooted)