Point cloud artivacts on different height?

Hi, from time to time I notice strange artifacts in the 3D point cloud view. Parts of the

As you see there is a similar copy / extract of points on a slightly different height level, ‘flying’ above the ground point cloud. Fair to say, that they disappear after some time. This is currently around the bridge here:

Is this known bug?

Seems like point clouds are only generated per sequence, and not connected. Some time ago I noticed a similar problem from top view: https://forum.mapillary.com/t/point-clouds-are-they-coming-back/1839/16

So a single 3D point is just created by pictures of one sequence but not verified / modified by others? Ok and all points are the sum of all points which explains the massive density by dublicate / close 3D points e.g. at street crossings. And yes of course this would explain this bug by bad heigth data and no fusion of the 3D datasets :face_with_raised_eyebrow: