When the user is redirected to /web/wicket/bookmarkable/org.geoserver.web.GeoServerLoginPage there are two different places to enter the username/password and they both share the same IDs. For most users this will not be a huge deal as the form still submits correctly. However, some automation has some issues with this and the debugger will flag it as an error in the console. This is a pretty minor issue, but as i didn't see any in the system i thought i should add it.
Thank you for your consideration.
Apache Tomcat 9, Geoserver 2.13.3