Lasso, what’s your bit rate there? Quantise value may be useful to us and also what sort of beat. Simple 8s on hat and bass / snare 4s etc. Does it affect all the kit beats or more evident on the hats say? Or. Did anything disappear when you did the phase inversion? What I’m trying to get at is is it the whole track or just the parts within. Get the info line up at the top, highlight the two tracks one by one and see where they start. If one starts different than the other then it’s the whole track moved.
Is this evident on other VSTis? (honest it started out as a one-line question?!)
And could it be connected to something like the snap quant value? Though it shouldn’t matter on a straight duplication but you never know sometimes.