as a visual quirk, it is impossible to see a 1x1 darkness on stairs up and other tiles like wall illusions. There are other spell graphic effects that get suppressed in similar ways in the layering with certain tiles or decorations. [Reported by Vernak]
Tagging this worldforge since it sounds like a component issue? @yarrim @jkachhad might be able to provide more feedback here. My assumption is whatever fixes this fixes a lot of the other issues similar to this.
as a visual quirk, it is impossible to see a 1x1 darkness on stairs up and other tiles like wall illusions. There are other spell graphic effects that get suppressed in similar ways in the layering with certain tiles or decorations. [Reported by Vernak]