I think what you might be running into is the change of Legacy materials and the move of Rhino 6 toward a different way of rendering. Rhino 5 had very little rendering on its own, so it was all Flamingo that was in control. Now in Rhino 6, there is a bit more support for texture mapping on each object. So, yes, sometimes that texture and tiling is control on each object. Now, the good part is you can probably edit them as a group of objects.
Where we run into trouble here is the legacy way of render is different in Rhino 5 and Rhino 6. If we can see the examples here we can untangle how the materials an tiling is put together on this model.
We find this confusion when people have been using Flamingo for a long time and the new rendering tools in Rhino 6 start force a different way to working a little.