I have seen the same thing with zoning, 2x2 holes, I mostly let it naturally rebuild around it and then re-zone to fill in the holes. Then the building are 1x4 stacked next to each other,

After growing to highest level, the building disappears and a zoning hole is left in the zoning area.
(i.e. the 4x4 zoning has center 2x2 reset back to no zoning, only the outline 12 blocks is still zoned.)

This happens to all your highest level 4x4 buildings, presumably because of the sub building that adds glass. Any way to prevent the zoning from disappearing?

@Radltruhe can't fix that, it's due to the game - the glass parts for the outer balconies all have the same name, that's why there is this Duplicate prefab name, but you can easily ignore this error :)

Please fix:
Custom Assets: 611089175.QM_Glass_RV_Data: Duplicate prefab name
at PrefabCollection`1[BuildingInfo].InitializePrefabImpl (System.String collection, .BuildingInfo prefab, System.String replace) [0x00000] in <filename unknown>:0 [Core]

fit well in the -GERMANY- all in one Collection:
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=477181517
thank you, Thumbs up