Wis. Stat. § 618.44
An insurance contract entered into in violation of this chapter is unenforceable by, but enforceable against, the insurer. The terms of the contract are governed by chs. 600 to 646 and 655 and rules promulgated thereunder. If the insurer does not pay a claim or loss payable under the contract, any person who assisted in the procurement of the contract is liable to the insured for the full amount of the claim or loss, if the person knew or should have known the contract was illegal.
Wis. Stat. § 618.44
Nothing in the text of this section suggests that an insurer's having been joined as a defendant prevents a plaintiff from also seeking relief from an insurance agency. What matters under the statute is whether the insurer has refused to pay a covered claim before the plaintiff files suit against the agency. Midwest Commercial Funding, LLC v. Cincinnati Specialty Underwriters Insurance Co., 271 F. Supp. 3d 1040 (2017). An insurer "enforces" an insurance policy against the insured by collecting the policy premiums. Refusing to pay a claim is not enforcing the policy. It is the insured who seeks to enforce the policy by making a claim for benefits. When the insurer denies the claim based on a policy exclusion, it is simply defending against the insured's claim, not prosecuting its own claim for enforcement of the contract. Midwest Commercial Funding, LLC v. Cincinnati Specialty Underwriters Insurance Co., 399 F. Supp. 3d 736 (2019).