Ok I found out what the issue was: my point clouds didn't like being imported into a georeferenced file. When I import them into a new blank document with the User Origin + Internal Origin both at 0,0 in the page centre + select ‘Center Import on Internal Origin’ in the import dialog they display like they should do:   So in order to import point clouds into my georeferenced file + have them display without half the points missing I have to first set the user origin to the intern