Traefik host apart from .com or .org

I have the following ingress-routes

apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
name: app-route
namespace: default
spec:
entryPoints:
- web
routes:
- match: Host(frontend.app.localhost)
kind: Rule
services:
- name: app-frontend
namespace: default
port: 80

In my /etc/hosts:
192.168.10.0 frontend.app.localhost
Here:
192.168.10.0 is the external IP of traefik service.

When I put frontend.app.com the following works.
But frontend.app.localhost fails. Why is this happening ?

It seems *.localhost may always be resolved to 127.0.0.1 by the browser.

Related post about curl via Docker forum.