Sanity check about drum editing

Using MuseScore 2.03 while editing the Drum Note map while a drum pattern is present, if I press APPLY there is no change shown on the score if the staff number is changed for a particular drum piece: e.g. a snare from line 2 to line 3. If I Press OK, then the change occurs after the dialogue box is closed. This should take effect once APPLY is pressed, not only with OK. Can someone verify this isn't just my system?