Core

Live WS
Initial page tree situation:

+---[1] First
+---[2] Second
+---[3] Third

Displayed navigation in frontend

First |  Second | Third

Custom created WS
Create a new page "[4] Fourth" and move the page "[3] Third" as seen below:

+---[1] First
+---[4] Fourth
¦   +---[3] Third
+---[2] Second

If you now open the WS preview you will notice that the navigation shows something like:

First | Fourth | Second | Third

Comment
I would expect that the move placeholder of page "[3] Third" is not visible in the first navigation level any more.

Quick navigation snipp to reproduce:

navigation = COA
navigation {
    10 = HMENU
    10 {
        entryLevel = 0
        special = directory
        special.value = __YOUR_ENTRY_POINT__

        1 = TMENU
        1 {
            NO {
            }
        }
    }
}