I've been away from Ableton for a bit, but wondering if "disable grid snap" has always been on the cmd key?
because I usually change the note lenghts by increasing and decreasing the grid size with cmd+1 and cmd+2 and I could be wrong, but I remember always just keeping cmd pressed while clicking in notes to quickly just change the grid with 1 or 2, but now this is not working since snap to grid is on when cmd is pressed, so notes don't quantize to the grid.