The layout dialog does not show the names of the tracks in the Arrange window, but the instrument (track) names set explicitly for a certain track. Since I duplicated the track from the “Flöte I” track earlier, it took with it that name and did not update it when I renamed the track in the Arrange window.
I updated the alias name for that track in the Staff setting dialog to read “Bouzouki”, and now the names and track list shows correctly.
Sorry,
Christian