ArcGIS Pro scenes have an elevation service that is not in ArcScene. The 3D points from the poe data are below that surface and are therefore obscured. Once removing the scene's ground elevation via the Scene Properties dialog the points show up.
There is no problem with the surface view (elevation, contours, slope, etc) of the LAS dataset because that is placed in the 2D category in the Table Of Contents and is draped on top of the scene's elevation source.