plugin fails to load with systemd service

[TubadoG]

Gang, so sorry to post what seems like an easy problem to solve, but I've tried for about two weeks with no luck.

I'm running Homebridge on an RPi3, it works fine.
I'm able to run the node-dash-button node bin/findbutton command with sudo and sniff the ARP
I run Homebridge via systemd as outlined here.

PROBLEM:
When the service runs via systemd the node library returns permission errors. I don't understand how to modify the permissions or how to reference the library with elevated permissions.

ERROR:
[2018-11-23 11:11:38] Error: Cannot find module './build/Release/pcap_binding'
at Function.Module._resolveFilename (module.js:536:15)
at Function.Module._load (module.js:466:25)
at Module.require (module.js:579:17)
at require (internal/module.js:11:18)
at Object.<anonymous> (/usr/local/lib/node_modules/homebridge-amazondash/node_modules/pcap/pcap.js:3:21)
at Module._compile (module.js:635:30)
at Object.Module._extensions..js (module.js:646:10)
at Module.load (module.js:554:32)
at tryModuleLoad (module.js:497:12)
at Function.Module._load (module.js:489:3)

but as far as I can tell, I've set the perms for the library to be r-x for all users...

pi@raspberrypi:/home/homebridge/node_modules/pcap/build/Release $ ls -l -a total 64
drwxr-xr-x 4 homebridge homebridge 4096 Nov 23 11:09 .
drwxr-xr-x 3 homebridge homebridge 4096 Nov 23 11:09 ..
drwxr-xr-x 3 homebridge homebridge 4096 Nov 23 11:09 .deps
drwxr-xr-x 3 homebridge homebridge 4096 Nov 23 11:09 obj.target
-rwxr-xr-x 1 homebridge homebridge 45916 Nov 23 11:09 pcap_binding.node

All I can think is that I've installed the node package incorrectly, or in the wrong location, but I don't know... Any assistance would be greatly appreciated!