Call forwarding not working

[nameless00]

I'm getting a very odd behaviour with my call forward, if I set to always forward my call and it matches my main contact number (or so it seems), my receiver will ring once and then hang up, on the caller end they will get a constant busy tone. This was working probably until the last few days.

Oddly enough if I'm calling from another FPL number it will work, however, if I call a landline, cell, etc it will result in the behaviour I described.

Anyone else experiencing this problem?