Script stops running after screen lock

I hope I am describing this properly.

I have a Griffin Powermate that I use to control the volume of computer. I got it to work via this post (archived site).

file:///home/mspringer/Music/Griffin%20Powermate%20on%20Linux%20%7C%20screamingroot.org.html

I wrote this script: pmlogin.sh:

#!/bin/bash
rm /tmp/.evrouter:0
/usr/local/bin/powermate

I wrote this because for some reason, each time I run powermate I need to remove the tmp file.

Everything works fine but if after I have put my computer into suspend mode, when I unlock the screen powermate isn't working and I have to re-run the script.

My question: Why do I have to re-run it? Is there something I can change to make it persistent?

I am running Ubuntu 16.04 with Cinnamon Desktop.