Can you verify the following to make sure I’m understanding the issue?
-caller calls extension(no forwarding). call works fine.
-extension enabled forwarding to outside number.
-caller calls extension, and hears the ringback.
-forward destination answers. The call is connected, but there is no audio.
Does that sound correct?
-does it make a difference if the caller is an outside number, versus another internal extension?
-does it make a difference if the forward destination is to an outside number, versus another internal extension?
-if the call is answered and there is no audio, does the call eventually hang up automatically after about a minute?
One setting to look at in the FindMe/FollowMe Settings is Confirm Calls. If that is enabled, the call receiver needs to press 1 to be connected. If the announcement sounds are not set up properly, the receiver might not be able to tell what’s happening.