For some wall tops, the top texture or - usually more importantly - the bottom texture have the side texture applied. I've noticed this for both scooper walls, as well as the purple and yellow movie walls. (I also don't think a top for the cyan movie walls exists? Or if it does I can't find it.)
This seems like a non-issue, but can render the blocks very difficult to work with if you're building with any overhangs or whatnot. Attached image is a work in progress build of mine, and I have to either skip out on the top blocks or find a new wall set (because the room both has to be this height and has to have the archway that tall)
It's a very minor issue, but it's also an incredibly small and easy change as far as I'm aware, so I thought I'd suggest it. While it doesn't seem like it would affect many people, blocks with weird texturing things like this can end up annoying quite a few builders lol