Just checking! Well,stuff has obviously changed somewhat with the move to M1, but I am almost certain you should be looking at some difference in how your DAW is handling the created MIDI coming from MG2, rather that any bugs in MG2 at this point. When you play your guitar through and armed audio track with MG2 on it (I guess that part is similar to Logic or Abelton?), do you see any action in the “MIDI velocity” window?
Logic had some “Quick Punch-in” feature introduced for its latest version, messing with the input monitoring and the ability to play (and hear software instruments at the same time). Did you download a newer version of Studio One as well?If so, have you check the changelog, to see if they changed up some relevant functions?