Ahh if it’s the room I think you’re talking about you can move the black block up. You just have to go down first :) send me a pic on here if it’s something else.
I don't know if it was the same bug, but someone else pointed out an issue which sounds like it was the same issue you're describing. It was a bug affecting potentially 3 of the rooms. I've made a fix now if you're willing to try again. If it was this level pictured below then I have a version ready where you can start from here. Let me know!
Thanks!