Luke Letellier
SideFx support helped me figure out the issue: If the file paths for your files have a space between words, hbatch will not run and your background render won't do anything.
So if your file path is similar to #1, you need to remove the space between the words to look like #2:
1. /MyCompany/Client/Project Name/Houdini/renders/MySim_$F4.bgeo.sc
2. /MyCompany/Client/Project_Name/Houdini/renders/MySim_$F4.bgeo.sc
The same is true for the location of your HIP file itself; make sure the path doesn't contain any spaces between words.
SideFx is planning to fix this inconsistency, but it's probably a good practice for us to adapt our files paths in such a manner anywho.
Thanks for that info Luke, appreciate it