Various third party compressors acting strangely when receiving MIDI notes

I have compressors from several manufacturers that act in a really unexpected way when inserted on a channel that carries MIDI information in Bitwig. FabFilter Pro-C 2 gets forced into maximum compression when it receives a MIDI note. If you disable Pro-C, you can see on its graph and meter that now it's compressing properly. This in itself is a secondary problem, because it means that the plugin is still processing and eating up CPU. In all the other DAWs, when you disable it, Pro-C's meter goes flat, which is what it should be doing. Anyway, after some fiddling around I found out that I could put a Note Receiver in front of the compressor, mute the note receiver to strip out the note data, and then suddenly the Pro-C is compressing properly. Another way of doing this is to disable the MIDI listen feature inside of Pro-C, however this is still weird because the manual doesn't say anything about note data triggering compression. The MIDI listen on Pro-C, as far as I know, is only intended to map CC's to the controls - no notes. So there are a bunch of problems here.

UAD's Neve 33609, one of my favorite compressors, had a slightly different behavior. It appears to be working fine when enabled. When disabled, the MIDI notes force the comp to maximum compression. In the process, the CPU gets spiked because of whatever oddity is now going on with the comp's code that it wasn't designed for. You can literally watch the meters on the Neve plugin jump and come back down together with the length of the MIDI notes. Again, this shows that, when bypassed, the audio is still being sent to the plug and the plug is processing away, wasting resources.