we have configured /etc/maps/ for URL shortening, we used domain name to configure and URL shortening is working as expected.
We have few vanity URL's, those are not working, when we access with domain name, requests are getting appended with /etc/maps configuration, when we remove /etc/maps configurations, working as expected.
have you checked "Enable Vanity Paths" in your JCR Resource Resolver configuration ?
You should enable "Vanity Path Precedence" in Apache sling resource resolver factory" From OSGi configuration console. It will ensure your vanity URLs are cosnidered first before the sling mapping.