However, if I try running that loop from the workflow, then it doesn’t seem to work and I get an array of 18 nulls (the same length as the provided array).
Thinking this might be a bug/glitch, I tried recreating the loop function from scratch... Still facing the same issue.
I even made so that the multistep function only has a response step connected—which again works in test but not when I'm trying to run it from the workflow
Apologies for the confusion, from a quick glance it looked like everything was set up correctly. I had a suspicion as you did that it may be related to the {{value}} you were passing in, maybe that or another piece of data needed to be keyed into one more level.
And I was going to ask for a JSON export with some dummy data to test it out.
Does your last comment mean that on the second rebuild it is working now?
I wonder if connecting the loop to the step providing the data was the issue then