In 2019, the 6th Circuit held that American Family agents were independent contractors based on the Supreme Court’s Darden standard. This essentially considers “the hiring party’s right to control the manner and means by which the product is accomplished.”
This article from Faegre Drinker covers this in more detail
Investopedia says captive agents could be employees or contractors, but doesn’t cite a source
2021 1220 - JDSupra - Insurance Agents as Independent Contractors: Best Practices To Preserve This Status - [link]