Update: This is now fixed and was User Error... ID10T. I had made a change to the guitar and the output volume was just enough to register on the tuner but not enough to register coming out of the HD500X. I did reset the unit several times and reflash but believe the ultimate root cause was the added variable of the guitar output change (new battery turned out to be bad). Apologies if I caused any undue stress to those waiting to update ;)