Does 3CX System support 484 Incomplete Address response? I enabled it on a GrandStream GXP2020 phone and it doesn't seem to work. We use 9 to get an outside line. When I press 9, I get a dial tone but it doesn't accept any further inputs. Staff have been accustomed to hearing the dial tone when they press 9 and I'm trying to replicate the similar setup with 3CX. Any help will be appreciated.