After building and testing with lots of audit log fails, Brain finally admitted that my set up was correct but that it just can't do the request yet:
"However, your automation is likely failing because ClickUp’s API and Agent tools do not currently support programmatically setting or updating recurrence rules for tasks via automation or API. This is a known limitation: while you can update task fields, status, and other properties, recurrence settings (like "recur forever," "skip non-working days," or "on a schedule") are not exposed for automation or API updates. When it tries to set the recurrence, it fails because this action is not supported by the available automation tools. If ClickUp releases an update to allow recurrence to be set via automation or API, you’ll be able to automate this step in the future."