In Missouri, your ESA housing rights rest first on state law. The Missouri Human Rights Act (RSMo § 213.040) treats a landlord's refusal to make reasonable accommodations in rules, policies, practices, or services, when needed for a person with a disability to use and enjoy a dwelling, as unlawful housing discrimination. This state protection is enforced by the Missouri Commission on Human Rights and remains fully active. The federal Fair Housing Act (42 U.S.C. § 3604) provides the same obligation, and that statute has not changed.
Landlords in Cuba who refuse a valid ESA letter or continue charging pet fees may be in violation of the Missouri Human Rights Act and federal law. Complaints can be filed with the Missouri Commission on Human Rights.