I have disabled the few extensions that I have (advanced camera tools and sandbox tools), so they are not the problem. I don’t get pop ups and I did not yet use the configurator.
Actually I am working again on 2 projects that I started on Sketchup 2015, but that should be no problem and they are well organised, but quite detailed. Can’t really imagine that that should be a problem, but a very simple model with just two stories works well, there I get good plan views. So the problem seems to sit in the bigger more detailed projects.