In the interactive scatter plot, the navigation control overlay obscures the cluster legend when hovering in the area. The clusters can still be selected by clicking just off to the left for the time being. v4.0.1 in Safari (16.0) and Firefox (105.0.3) on macOS (12.6).
Update: I’ve also noticed that the layout does not re-scale following toggling of either the outputs group subpanel or sidebar. For instance, the cluster legend is obscured if the sidebar is expanded when it wasn’t initially. Somewhat similar to the behaviour in the Volumes panel reported here.