Hardware Compressor Sidechaining on Mixbus

I tried to search the forum to find an answer, but no such luck. I’m really confused right now…

I have a hardware compressor (ssl clone) that I put on the mixbus, wanting to use the external sidechain. What I want to do is have the external sidechain triggered from the vocals to compress the mixbus. What I did was duplicate the vocal track, and then made it’s output go to the compressor’s external sidechain input (in this case, Analog out 4). When i’m playing it in real time, it works perfectly. But whenever I try to export audio mixdown, nothing is sent to the sidechain input. I tried to make it the “main out”, I tried no having it be the main out. I tried to use the “direct output”, I tried a channel batch export, I tried to figure out how to print what I was hearing, to no avail, and i’m fresh out of ideas of how to do this. Is this some kind of bug? I see no reason why it should be working just fine playing it in real time, only to get absolutely nothing when i’m trying to export the track. I’m on Cubase Pro 8.5.20 for OSX. Any ideas would be greatly appreciated.

You are doing a realtime export, arent you?
If so, make sure the track is not record-or monitor enabled, and no preference is set to do that automatically on record.