Hi,
I have checked your website and I see that there is no much space for the language flags and the dropdown selector to fit in one row. You can try to add the following in Custom CSS section: a[data-gt-lang] {display:inline-block!important} and also you can uncheck “Line break after flags” option.
I recommend you to use Flags with language names widget look with Show in Menu option, so it can display the current language and a submenu dropdown with other languages like you have it for “About Us” in your menu.
Thanks! 🙂