Cross staff notes retain top staff modifications
Save me from my inability to title an issue.
Anyway, here's a picture.
The way that would be played is 8va on all the top staff notes, and regular on the bottom staff. Musescore 8vas all of it.
There is a huge amount of cross-staff problems, but I don't think this one is documented?
Workaround is fix-to-line the wrong notes, and knock them down an octave. Very time consuming.