Thank you. Shows that it is doing exactly the same without the HOST.<https://github.com/coreos/prometheus-operator/blob/c8eb45194a9115f37b64f3a3084c34dee4f8972f/test/framework/ingress.go#L34>
In my test, I removed the HOST info but I did not add a PATH. Maybe add the path will allow the OCP to recognize it as a route object. It could be a solution.