Problem insert chords with qwerty and lock duration

When I insert notes through qwerty keyboard it follows normally heights of the notes. Typing C, B, A, G will insert notes down.
When I insert the second stem (without making an new voice) for some notes I set CHORDS and LOCK DURATION ON. The inserted notes are alway above the first notes. When I change this an octave lower and press arrow right to the insert the next note then this note will be inserted above the notes instead of following the hiehght of the previous note.

Maybe this can’t be changed, maybe it’s a little bug.
Schermafbeelding 2017-05-29 om 14.34.15.png

It is intentional that when in chord mode, every note you input goes above the one that’s already there, so you would have to use Ctrl+Alt+letter (Windows) or Control+letter (Mac) to make the new note go in below the existing one.