Sidechain "Key" in is not saved in scene or show

Hi.

Can someone try this at home? :D
Made a compressor setting where the vocals are the sidechain input of the compressor of the guitars. so everytime they sing - the guitar goes down 2 or 3 db.
So - made a scene - set this up - saved it - saved the show at the newest offline software version. (4.5.1.42)
So - if i recall the show and the snapshot - the key "in" is gone.
It seems like that this is not saved in an scene.
Can somebody please try that?

Thanks
Albin