I flashed MB1, MD4, then MK3 but that didn't help. Right now I have it in CDMA/LTE mode and it's connected to CDMA eHRPD, every once in a while I will lose signal and regain it, I assume this is when it tries to connect to LTE. I will try to do another hands free activation later today when the phone has no problems connecting to LTE.
I haven't tried ODIN to stock, I will do that this weekend if everything else fails.