Customisations are not applied remotely

If the sidebar customisations work perfectly when you are connected through your local network but they don't work when you are connected remotely, most probably you are suffering from caching issues. If you are in a browser, open the developer console, go to Network and check the checkbox labeled as Disable cache, refresh the browser with the developer console open. If the issue is only in the Companion App, consult Issues with the Companion App.