Yes that is normal. Matrices do not work like Subgroups or Auxes. The button Mix/Fx are for what its names state, to mix and DCA Groups move in the other auxes, but not in Matrix, because you have setup some DCA in the Auxes, but not in the Matrix, if you setup at least one DCA in the Matrix, then that button (DCA) will work. The mixer is not intended to press buttons randomly and they must move something, everything must be thinking first of what you are going to do, and that logically will move or not move settings. Anyway, I understand, you are happy and having fun with your mixer, tat is great, welcome to PreSonus Users.