after I upgraded to 18.104.22.168 the call waiting stopped working, I get no notification if I am on the phone and another call comes in. 2 of them were for a customer and came with that firmware, in an attempt to figure out the issue I upgraded another phone and it did the same thing.
the call waiting works properly on the other phone models.GXP2170 with firmware 22.214.171.124 I cannot get anyone to call me from grandstream I have enabled and disabled dnd. I have tried downgrading to the old firmware but nothing happens
So in case this happens to anyone else, I had to move the 2nd vpk down and set it to default. you cannot use the vpk as a speed dial in the second slot.
You can but you need switch VPK mode to account (it is really bad described)