This is the most plausible explanation so far. A visible fault that can cause symptoms exactly as observed. All unmodified minis I've shot have ejected casings at least 15ft if not even further and if that's not happening the first suspect is some kind of restriction in the gas system. Misaligned gas port due to canted barrel would fit the description to a tee.The two issues may be related it might be that your Barrel is canted One Direction in the gas Port isn't lined up with the bushing this would also mean that your side is way to one side
LoonWolf, you were right on the money, barrel is canted!!