New admin page: "Enable Polling" button disappears after disabling polling and reloading page

When you go to this URL on a slave:
http://localhost:8983/solr/#/singlecore/replication

And click the "Disable Polling" button, you see a red bar that says "invalid_master". I'm not sure why I get this red bar, as I haven't tested it outside of my own installation, but it seems normal.

If you then refresh the page, the "Replicate Now" and "Enable Polling" buttons disappear. It seems like their generation is being interrupted by the "invalid_master" error.