Swapping locations between father/child makes them loose main location until ezplatform caches are cleared.

In EZP-26364, petar.spanja@ez.no referres another situation that I don't think it's the same referred in here, thus this new issue. But please evaluate if the solution might be the same for both. If so, the current one might be considered as duplicate.

Steps to Reproduce

1 - Create two folders, where one is the child of the other
FolderA
-------- Folder B
2 - View Folder B and swap location with Folder A
3 - Now see the Main location both for Folder A and Folder B. It's not set.

After ezplatform caches are cleared, we can see that Main locations are set again, so this seems to be a cache issue.