Strange rename on network redirector

NTFSD
1

I noticed strange behaviour of rename operation on network redirector, I
have opened FileObject from \server\whatever\path\file.txt where
\server\whatever\ is sharename .
Set rename information with

ReplaceIFExists=FALSE
RootDirectory=NULL
FileName = “newfile.txt”

and post IRP, in almost every network scenario this thing works as
expected, rename will change \server\whatever\path\file.txt to
\server\whatever\path\newfile.txt

But I have one client where this rename, leads to
\server\whatever\newfile.txt
so file is moved to the “root” of share. Any idea ?

Martin Hron