That is exactly where I suspected the leak was too, but I performed an autopsy and at first was surprised to find where it was, then it made sense. On this one, it actually happened where the tube goes up the chimney. Looks like at the layer where the deck starts, it starts under-extruding there for some reason, and there was a square tube layer that basically had no adhesion. Maybe because it starts doing more travels, or maybe the square tube layers start cooling too much while it is doing the deck top/bottoms, or both. Not too sure how to work around that during the print. I might try to fix my other leaker by drilling down the chimney just past the deck layer and printing a round tube to glue in.