Recursive workflow not reaching second item in list

I’ve been trying to recursively call the Printful Mockup Task Generate API on a list of variant ids, but the API returns a 400 error once it reaches the second item in the list. For context, I have a list of variant ids (these are just numbers) in the Bubble database that I send to the API, which takes the variant id and creates a task key. The task key is being successfully created for the first variant id in the list, but once the workflow reaches the next variant id, this is what happens in the server logs:

The call seems to be working fine in Postman, and I’ve tried different things like adding headers and calling from a repeating group of variant ids rather than the database, but nothing changes. Any help on this would be appreciated!