The system of snap-to-point cloud data has two levels: basic – snap-to-point geometry, and advanced - 3D snap-to-parametric geometry recognized in a cloud. Basic snaps are activated by the “Node” type (snap settings manager in the status bar) and are managed by a checkbox in the ribbon (Point Clouds section -> Settings -> Snap Point Cloud).
Advanced ones are activated by a set of Point Cloud Snap Modes ("Point Cloud. Edge Node", etc.), in the 3D snap manager in the status bar and are managed by a checkbox in the ribbon (Point Clouds section -> Settings -> Snap to Features)
But for 3D snaps to work, you should first recognize the geometry using the tools in the "Features" section of the ribbon