Popular compiler arguments list is truncated on the right side if the compiler pane is right-most. It does not depend on a browser window maximized state.
Tested in Firefox and Chrome.
Screenshot:

Thanks for filing this; yes it does seem to be a problem!
I still observe the same bug. Nothing changed. Both in Chrome and Firefox.
the fix is in master, but has not been deployed to the live site yet.
Whenever we deploy next you should see the fix.
We should be deploying later today. Thanks for your patience.