Small spring app deployed on Wildfly returns a 403 on home page but works when deployed as spring app.

I have a minimal Spring project, with just one Controller that returns a static string, and no security.
When I deploy as a Spring Boot Application, it works fine and I can access the endpoint.
When I package as a war, and deploy to my Wildfly Server then requests to that endpoint return 403.
There are no error messages in my server.log.
My standalone xml and conf are the out-of-the-box ones from fresh install.