Newest version of my build did NOT have the bugg.
In the new version I moves the clutter.
A new save, with mods on, downloading it into the lot and fixed:
https://i.gyazo.com/bb8d607abafe0e26fa2767ba544b54e6.jpg
I don't know if this is because I moved the clutter, or because I uploaded from a save where I had mods turned off in order to 'cut out' the lot trait mods.
I suspect the mods - so I just recommended them in the comments instead.
So the upload has no mods, yet my save has mods on - and it works. As well as working when my save has no mods.
And if it's a bug that only occurs when using lot trait mods with a residential rental (skating ring, movie theater, basketball court, and employees | Professional)... then it's not a bug.
So I guess 'solved / case closed.'
