Cleanup walls by border

[staler.pc]

Hello! I have a file with walls which cleanups to each other if their border is intersected and baselines don't.
But I haven't any idea how it happens.

What the property should I change to use this function?

The file and screenshot is attached.

[David_W_Koch · Accepted solution]

The horizontal Wall has been merged to the vertical Wall.  Remove the merge and there will be no apparent cleanup.

You need to turn on Justification Display in order to see the dashed arc that represents the Wall Merge.