Same part definition,
same file,
same dynamic, promoted view...
Different outcomes.
One element gets painted with the forward projected geometry pattern(cell) map, as defined in the material attached to the part definition. Its neighbor doesn't.
Looks OK in the model or with a live view, until that view is cached. Also same effect when printing the dynamic viewt, unless rasterised is ticked.
Could it be a complexity issue? Its only a single wall with several window openings.