Default Backend in RKE

Hello, Rancher Experts!

I am about to using the option “User as Default Backup” in Ingress, but I cannot get it working. I want, that all unresoved requests are redirected to my default backend, which is Tomcat in my case.

But it doesn’t work, I still receive standard 404 Page of the ingress. Do Anybody have an Idea?

In I read " NOTE: If you deployed Rancher using RKE, a default backend for 404s and 202s is already configured." Ist it probably the cause of my problems?

Thanks a lot and BR!