Possible problem with XREF scenes and distributed rendering

The issue should be related to this specific scene or setup because X-ref scenes are rendered fine in DR mode in V-Ray 3.3.
Is there any chance to try your Xref scene here ?
Have you checked the V-Ray log on one of the salves machines ? Is there any useful information - error or warning ?

Just did a test with X-Ref scene with both “Visible” and “Box” Display Options ticked and that worked for me. Could you please provide more details or step by step instructions on how to replicate this behavior here?