Problem With call transfer for 1 extension

Hi everyone

I need some help with this.
I have a Polycom phone with 4 active lines for in or outbound calls used by the receptionist.
The problem comes when the 4 lines are ringing, then pickup the line 1 and tray to transfer the call and got a message saying “wrong port”. Maybe, because all the lines are busy… right?

well… I was reading some manuals to solve this issue… and found the command “call-limit” to limit for 3 lines and use the 4th to transfer calls… but still not working.

Hope you can help me