What about on the suppressor side?

Just to be clear... what is the white stuff? Is that the Rocksett on the muzzle device?

I don't have any AAC cans, but I would put my bet on something on the mating surfaces was causing an uneven blast wobble or it could be a minute uneven space on the barrel itself. For example, when I got my very first can I was excited to try it out so I just put the MD on the gun without timing it. Later on in my evaluation even having the orientation of the bare MD altered would change my POI by a lot. It was very noticeable.

I don't know how locked up that can gets when mounted, but if there was anything caught in between the can's mating surface and the MD's mating surface it can cause things like this. It can happen if the shoulders of the barrel are not exactly even on both sides as well. Both of those things will induce things like this. I helped one guy who had terrible horizontal stringing so I had him remove the MD, clean everything with a stiff brush and install again with shims which he did not have the first time. Problem went away with about 15 minutes of easy work.