Back end doesn't update frontend correctly incase menuitm is linked to sitemap item which has the same name as of a folder under documents

Steps to reproduce:

1. Go to channel manager in edit mode
2. Click on menu item link to open menu editor
3. select one of the existing menu items or you can create a new one.
4. select internal link option and open the link picker
5. now select "Page sitemap item" under dropdown.
6. Select a document with the same name as of a document/folder under documents section. eg."news" which is present in both
7. Click Ok and save your changes.
8. Now select the same menu item for which page-sitemap item was configured.
9. Notice instead of showing "news" under "page-sitemap item section for the menu item.It shows "news" as selected under Documents section.

Note:Frontend probably gets confused to which item this menu item is linked because of the same name of the items under documents & in the page-sitemap item .
Also, backend doesn't provide clear information in same name item case.So frontend defaults to "Documents" and shown it in UI.

Expected:Above behaviour should be fixed.