Please see our Troubleshooting guide for finding the underlying error:
https://wiki.lyrasis.org/display/DSPACE/Troubleshoot+an+error#Troubleshootanerror-DSpace7.x(orabove)
When there's a very odd behavior in the UI, it's almost always caused by an underlying error message. I'd recommend checking your browser's DevTools for odd responses from the REST API, and also check the backend logs (dspace.log and Tomcat logs) to see if
any errors are occurring there (especially when you login as an Administrator).
You also may want to see if refreshing your window changes the list of options. There's a known issue with Shibboleth based authentication where the sidebar sometimes doesn't automatically load properly:
https://github.com/DSpace/dspace-angular/issues/1515
If you are logging in via Shibboleth, it's possible you are hitting this -- if so, the menu will load properly if you click reload in your browser. (Obviously that's annoying behavior, and we are working on a bug fix for 7.4)