Note input associated with wrong staff (0.9.6 regression)

1. Create new score for piano
2. Press "N" to begin note entry and select quarter note duration
3. Click to add note to first measure of top staff
4. Click to add note to second measure of bottom staff

Expected behavior: The quarter note from step 4 should be associated with the bottom staff only

Actual behavior: The quarter note from step 4 appears on the bottom staff but it affects the rests in the top staff as if it were actually part of the top staff. Is also impossible to add more notes to the rest of second measure in the bottom staff.