Why would the ILS Glideslope and the Papi Glideslope not match?
Seems like a recipe for disaster right there. It would explain why the touchdown point is rather variable!
Terrain/buildings, you are flying down a hill. The G/S is set at 3.2 deg, more than what it normally is, procedure is to go visual when able. Many a pilot are not prepared and fly the G/S all the way in. I have a great video on FB of a procedural landing in a DC-10-30 in less than optimal weather. (corrected G/S, my error)