Using with Sinden Guns via Batocera

Ok... granted.  This is a very narrow use-case, but I'm hoping someone might give me some debugging guidance.

I have set up Batocera (Linux-based arcade emulation) to stream to my Nvidia Shield Pro 2019 using Moonlight/Sunshine.  Works great.

I have two Sinden lightguns that I plug into the Shield running the VH Server and am running the Linux client as a daemon.  VH sees the guns, allows me to use all the devices (each gun has two devices), but I the cursor stays stuck in the upper left corner of all menus/games.  I can use all the buttons/triggers on the guns to navigate and Batocera shows I have the guns connected, but it doesn't seem to be sending the cursor/mouse movement data over VH.

I can, without a problem, run the Windows VH client and stream to the Shield using Moonlight/Sunshine and the guns work perfectly via VH.  But for some reason, they don't seem to like the Linux client (I think).  

I confirm using the "LIST" command via SSH that the devices are in-use (they even auto-connect after I executed the "AUTO USE DEVICE" command), but I'm not getting cursor movement.

Is there a way to see in any log file whether the mouse coordinate data from the guns are even being sent via VH?  That will at least let me begin to figure out where the problem may be.

Thanks!