Walls on different levels are connected to each other

[sluijmers]

When we model a wall on a level with unconnected height and copy that wall to the selected level above or below, Revit gives a message the walls are overlapping. We adjust the constraints of the walls so the overlapping is solved. After that the wall ,on for instance level 1 ,is connected to the different wall on level 2. So moving the wall on level 1 also moves the wall on level 2. The reveal constraints show no connection or lock. When we pin one wall and move the other the message appears that the walls can not stay joined. So we click unjoin. When we move the wall to the same place the walls connect and join again. We have a lot of problems with this invisible connection.  Does anyone have any idea how this works and how we can prevent it? 

[jay_colcombe]

This is an old issue and it stems from a typical scenario is that when the walls were initially added they were overlapping geometry between levels. When modified later to be associated to another level, or the offsets were modified, the walls have remained in a joined status.
Should you come across this behaviour, you can simply Cut & Paste Aligned one of the level's walls to the Same Place to reset the association. 

Walls on 2 different levels joined? - The Revit Clinic

[sluijmers]

It does not have anything to do with the fact that the geometry overlapped. Even if you adjust the walls to the right constraints so they do not overlap while pasting to a selected level the connection is still made. So there is basically no way of preventing this only to deal with it......which is basically all Revit is about. 

[jay_colcombe]

I must be doing something wrong then as I have no issues here when the Level Constraints are correct prior to Copying and Pasting