I cannot get my headset to pair with my wife's. Turn on and set to pairing mode. Blue and red lights flash and just continue to flash for several minutes. I have paired my headset to my wing and to my phone. I also have paired her set to my phone so I know both sets do work. Clear pairing by holding multifunction button and volume up which turns it off but should also clear all pairings. Still won't pair to each other. any ideas what I'm doing wrong?