Issue with building parts marking other building parts as owned

[MRVDH]

• "I bought a building and every building showed as owned, even ones way above my level. It didn't count as me owning or buying them and I couldn't do anything with them though." http://prntscr.com/uo1fjd (death2636)
• "Found an issue where buying some buildings that are split into parts cause you to gain the other section for 'free' but not the income from it." (throwaway040501)
• "Sometimes, two buildings may overlap, in which case buying one building sometimes buys the other building for free. Treat these buildings (with same ID) as one building and calculate their stats accordingly (including total net area and average height)." (James103)

[James103]

Here's a small excerpt of my list of owned buildings that shows that one of the buildings that I have bought does not have an ID, which may cause all buildings to be marked as owned:

Edit: I was able to find the offending building on the game map. To find it, use this link: https://mrvdh.github.io/budongsan/#15.94/38.515798/-89.978166 and click on the building highlighted (with the grey square) in the following screenshot.