Chances are, it's something to do with that tile for the table.
I tried replicating this on Forest Town Inside, but I couldn't do it. It was always over the table, not the other way around...Perhaps there's some tileset settings that are causing this thing (Particularly the table middle).
Maybe it's the event. Copy all coding with the event, delete it, make a new event, paste that coding in there, and then change the graphic back. Perhaps that'll work.