Only the belt coming in from the west has a preview (with the color for extra milestones), is it because it's the only one having more than one shape in the whole three levels?
#Missing shape dropoff preview at the vortex
plain turtle
plain turtle
now a preview has appeared, but it's for a shape that isnt in the belt
but the one from the shape i just added does have a correct preview
fresh inlet
Shape previews show what the factories upstream are making and not what 's currently on the belts. Double check something didn't go wrong with your factories.
plain turtle
doubled checked and there's no grey squares in the upstream (blue squares are cobbled together from a shape with a blue corner)
but also now that one stopped appearing once I added an input in the bottom belt
now it just (correctly) shows the bottom belt
mental fulcrum
Usually a broken shape preview like that means that there's a problem in your factory somewhere upstream. The shape preview is always the steady state shape: The one that, if you wait long enough, will arrive at that spot. But if something is broken or jammed upstream and the flow will stop once all the shapes in the belt clear, the shape preview tends to vanish.