Hello,
Dirk sent me, try to bypass the gimbal, take the camera OFF the gimbal, hook the phone jack into it WITHOUT the gimbal jumper wire, like it was originally , see if that works! ( if you get telemetry back or not ) as those gimbals block out 1 internal antenna, this could be the problem, if other antenna is malfunctioning or something! Try this first!
Could be just a faulty wire, or blocked reception, ect! If not we will try something else!
Keep us updated!
Next I would reinstall all firmware, Tx, bird, ect! You may have to update firmware, or reinstall it to FC200 camera ( via memory card ) we will get you there, no worries!
J Dot
Take care, Fly safe!