Conn standalone vglrun display issue

With version 16 of standalone conn I was able to open using ‘vglrun conn’ but with 17 and 18 (matlab/R2017a), I can no longer open conn, getting the error:
[VGL] ERROR: Could not open display :0

I am pretty sure my cluster isn’t having VirtualGL problems because I can open other programs with vglrun, e.g., matlab, firefox. I followed the instructions here (https://sites.google.com/view/conn/resources/installation?authuser=0) and have tried using MCR installed on its own and through a matlab module.

I can get standalone conn to open without vglrun, so I’m at a loss for what the problem is. The only thing I can think of is that the folder MCR/v92/X11 doesn’t exist, so XAPPLRESDIR isn’t going to be set correctly. There’s no X11 folder in the matlab installation either though, and that opens with vglrun.

Here’s the full command line output:
[joseph.orr@gfx ~$ vglrun conn
[VGL] NOTICE: Automatically setting VGL_CLIENT environment variable to
[VGL] 165.91.12.191, the IP address of your SSH client.
Initializing MATLAB Runtime version 9.2
Loading MCR. Please wait…
[VGL] ERROR: Could not open display :0.

My LD_LIBRARY_PATH is set to:
/fdata/scratch/joseph.orr/software/MCR/v92/runtime/glnxa64:/fdata/scratch/joseph.orr/software/MCR/v92/bin/glnxa64:/fdata/scratch/joseph.orr/software/MCR/v92/sys/os/glnxa64

My modulefile is doing:
[joseph.orr@gfx ~$ module show conn
-------------------------------------------------------------------------------------------------------------------------------------------
/apps/psyc/psyc-modules/conn/conn18a.lua:
-------------------------------------------------------------------------------------------------------------------------------------------
conflict(“matlab/R2017a”)
prepend_path(“PATH”,"/apps/psyc/conn/conn18a")
setenv(“MCRROOT”,"/fdata/scratch/joseph.orr/software/MCR/v92")
setenv(“XAPPLRESDIR”,"/fdata/scratch/joseph.orr/software/MCR/v92/X11/app-defaults")
prepend_path(“LD_LIBRARY_PATH”,"/fdata/scratch/joseph.orr/software/MCR/v92/sys/os/glnxa64")
prepend_path(“LD_LIBRARY_PATH”,"/fdata/scratch/joseph.orr/software/MCR/v92/bin/glnxa64")
prepend_path(“LD_LIBRARY_PATH”,"/fdata/scratch/joseph.orr/software/MCR/v92/runtime/glnxa64")

Any suggestions?