I already tried it with the WIFI off. Doesn't work. I can see UMA interfering if I was on a call or trying to make one. This piece of junk won't even pair with the 0000 passcode. 2 diff BT headsets due the same thing. It sees the headset asks for the code and when I put it in, it comes back asking me to enter it again over and over again. I did search and I remembered reading someone else had the same pairing issue.