I'm not sure I understand your message, or even your video.
Normally, purging the cache (not the file cache, but the main menu option) should work.
There are a few glitches when manipulating languages on the language edit page. I'm aware of them, but they only happen there, AFAIK, and they disappear after a couple of reloads at most.
The only problem that happens on all pages is that if you empty the cache, the language selector will show all installed languages (not just the allowed ones), but this gets fixed automatically on the next page load. (So, basically, just reload your page after a cache purge.)