I just purchased 10 Voyager 104 headsets. I have 10 GXP 2135s all on firmware 184.108.40.206 (the current latest). These headsets are Bluetooth and are on the compatibility list for the 2135s. I have found out the hard way these ARE NOT COMPATIBLE and have a MAJOR FLAW. This is a small call center I bought these for and it does this on every single phone.
Randomly during a call the grandstream phone thinks the headset disconnects from Bluetooth and changes the phone to speaker mode all while the whole time the headset still works and you can hear the call out of it and still talk through it. I have duplicated this issue with 10 headsets on 10 phones.
There are only 3 Bluetooth settings in these phones none of which make any difference to this issue. This is a warning as I cannot return these headsets and am out almost 1k. Thanks grandstream for your extensive testing.