Workflow API doesn't create things when ignoring privacy rules/running without authentication

I want to use Workflow API to create some things in my Bubble database using data from external sources (let’s say my other site). Currently I have Workflow API enabled, but not Data API; from the wording on Bubble’s manual page on Workflow API, I assume it can create things with Data API disabled. The things that need to be created are checked in the list that appears below ‘Enable Data API’ even though I don’t use it (in case it’s important).
On the main workflow itself, it’s set to run without authentication and ignoring privacy rules. The first step is creating a thing in my database. This doesn’t happen!
I can see that Bubble receives and interprets the request, because while testing, every time I click on ‘Modify types’ on the workflow, it gives me the data of the latest request i had just sent. So it seems like Bubble sees this request but doesn’t go through with the first step, even with all authentication and privacy restrictions lifted. It’s likely I’m missing something obvious here but right now I just can’t see it.
The workflow in the inspector:

The first step: