Cloned track side chaining crash issue
So I have run into a strange problem that I have never encountered before, and after lots of prodding and probing, I think it may have something to do with cloned tracks and side chaining.
I cloned a vocal track without events, just to quickly have a vocal track ready to go with the same i/o, fx etc as the original. Recorded a vocal section on it. This second vocal overlaps the first vocal and needs dominance, so I added a compressor to the first vocal and to the second vocal I added a send to the SC of the 1st vocal's compressor. Bang! I had cans on at the time and the SPLs squeezed my brain into a small ball from both sides - a hideous, loud noise and multiple, unrelated meters in the red in Sonar. I had to kill Sonar then try again, but having strange crashes and explosive sounds each time. It's like there's some horrific feedback issue going on which is so intense that other channel meters come out in sympathy with it! I have tried several different compressors.
Setting up a side chain on another channel works fine, it's just between the vox channel and it's clone that the issue arises. I assume it's something to do with the cloning process as everything seems to be routed as it should be. I know that when cloning an instrument track if I change the soft synth in one, it changes it in the other too. So my hunch is that there is always some deep connection between cloned tracks even though they appear to be separate. If that is the case, how could one separate them into independent tracks?
Any ideas what's going on here?
Splat, Win 10 64bit and all sorts of musical odds and sods collected over the years, but still missing a lot of my old analogue stuff I sold off years ago.