Output Routing in mixer

I try to sidechain my kick in the mixer and in the routing section I pick no bus but it defaults to the nearest group bus it wont stay on no bus is this a setting a can not seem to find it

Explain the whole routing. It’s not clear why you would be trying to select no bus for side-chaining

I was getting that the other day when setting up a cue mix for reference tracks.

It was always the first audio track I created refused to be routed to no buss. The second would be fine.