Removing a hierarchy node doesn't seem to work

0. Run in debug mode.
1. Open a project with one photo, no segmentation ever attempted. The default region hierarchy is shown in the panel on the right, as expected.
2. Right-click head, select Remove label. Unexpectedly, nothing happens.
3. Right-click body, select Remove label and children. Unexpectedly, nothing happens.

(Not even newly added nodes can be removed.)

For consideration: Right-clicking specimen also offers Remove label and children. Should this even be possible? How would one create any other node in the hierarchy, if specimen gets removed?

Even if this isn't implemented/fixed, right-clicking the label list should at least be disabled in the release version.