CID is not showing correctly on follow me setting

Hello:
The caller called my pbx and the call directed to one extension, Nobody pickup at the extension, then the follow me executed. In the follow me form, I put an cell phone number there. The cell phone rings but does not show the caller’s CID. Instead showing my pbx trunk DID. I did not put the DID number on the trunk setup form for the outbound caller id. But it still shows up. Anyone has any idea what should I do to get follow me to show the correct caller’s ID, not my pbx CID.