OK, then I would try to get Paraview to work within an XFCE desktop manually to triage. Indeed any vglrun command withing the desktop may shed light on this. Maybe MATE may not be the right path yet, as it could be heavy lift to migrate this.
If a plain XFCE desktop works, then trying to get vglrun paraview to boot manually within that desktop session would be our best bet to troubleshoot. That way we replicate the environment of the job, have a good $DISPLAY already set and so on.