Wrong voice button is highlighted after unsuccessful voice change
opening the attached excerpt with musescore/master, it seems impossible to change voice for the two bottommost notes, namely trying to move from v2 to v1 (Ctrl-Alt-1, or press the "1" button) for the bottom-left note, or trying to move from v1 to v2 (Ctrl-Alt-2, or press the "2" button) for the bottom-right one. I've got into this scenario by opening a MIDI file, then I just copied the troublesome measure into a new score to post it here.
I'm also attaching the screenshot of how the excerpt shows up, on my laptop (Ubuntu Linux 17.10 with system-wide Qt5).
This case doesn't seem to fall within the cases of (albeit it might be related to) the already reported issues about not being able to change voice on tied notes, or having troubles with voice changes for partial measures, or for a note in a tuplet, ie: