Engine controls changing on their own when selecting/deselecting engines

[Charon]

I've been flying the A-20 lately, with fully duplicated engine controls. Everything works great, except when I need to feather the engines. There's only one key to feather all selected engines, which means I need to select only the bad engine. As soon as I do this, all the engine controls go nuts.

 

In this video, I'm at 70% throttle, 80% RPM, Auto Rich mixture on both engines. I deselect engine 1, and engine 2 immediately goes to 26% throttle, 100% RPM, 100% mixture. I reset everything, reselect engine 1, and immediately both engines go to 26% throttle, 100% RPM, 100% mixture.

I don't have anything bound to the standard, all-engine throttle/rpm/mixture/radiator axes, and nothing else is bound to the 1 or 2 keys.