I have found this game easy, thanks. At least up until now.
I went back to a previous save again & searched that door from top to bottom, pixel by pixel and cannot find a hot spot anywhere in that vicinity except for the puzzle itself on the side of the door.
I see a step that looks like something's up with it but no hot spot there either. I went back to the front door but the only hot spot I found there is for the calendar. I'm stumped. I haven't touched the puzzle yet, just in case you or someone else remembers where that hot spot is.
I've been enjoying the game in spite of the hotspots. It's an interesting game & the graphics are good. I love Abigail's singing too.
I just hope I can get past this spot now.