Hey again Bre! Sorry for the delay here, I was checking with the Workflows team to see if they had any insights here. I suspect that there's some unsupported functionality here. It seems pretty common for a manual run to work but an automatic run to not work since the two ways to run a Workflow run differently. The manually run Workflows run client side and the automatically run Workflows run server side. Any sort of custom auth isn't expected to work, though it does seem like your query is pretty straightforward.
To double check, how are you automatically triggering your query? It looks like you're running it like SSGetOrder(order_id)?
If so, this may be the issue! You'll want to do something more like:
SSGetOrder.trigger({additionalScope:{order_id: 5}})
http://community.retool.com/t/how-to-use-additionalscope-in-your-queries/13343