Playback on parts

In musescore 2, when you made a part and played it back, it would only play the instruments in that part and nothing else. But now, in musescore 3, it seems to play every instrument regardless of whether its in the part or not.
Why was this changed, and more importantly, Is there a way to change it back?

or am i just doing something wrong?

p.s.
please don't tell me to use the mixer and turn certain instruments off, because then you'd have to manually do it again every time you want to change between listening to a part and listening to everything.