Making zero sized cifs files?

Trying to understand why my EX2 some times makes cifs files.  I use it as a storage device for archived movies.  My media player does all the media work, the NAS is just a storage unit.

Some times the EX2 makes these zero byte files that are CIFS.  Some times not.  I don’t understand the inconsistency of making them.

I have SMB and NFS on.  The media player I use works better when accessing the NAS using NFS.  Throughput is faster.

I’ve had other NAS devices, Lenovo dual bay and a WD 2 TB,  both support SMB/NFS and both are enabled.  Never see a CIFS file on either of those.

So what’s with these files?  Given they are zero bytes not like they are taking up any space.  Just curious…