Now I have the opposite problem...
I'm setting up a sidechain. I setup a new prefader send on my snare, and I want to use that to duck my synth. So, I set up a compressor on the synth channel, and set it up so that the sidechain input is set to the snare send just mentioned.
Now I should be able to solo the synth and tweak the compressor parameters to get the sound I want, but when I solo the synth, the incoming sidechain signal goes away.
This seems like a bug to me as the mute and solo functions should be at the same point in the signal flow as the fader.
I got around this by solo-safing the unused aux that got created when I created the new bus. Now it works as expected. Very strange stuff.