I don't know if it's just this room, but I found there's a section of the Mark Twain Steamboat room that doesn't allow me to configure furniture after placing it. I've added a screenshot-- it seems to only affect one area of the room.
I plop something in that Bermuda triangle, and it stays there unless I use the "clear room" function.
I plop something in that Bermuda triangle, and it stays there unless I use the "clear room" function.