Translations default to default language until language file is loaded

[micobarac]

I use three languages: en, sr-Latn and hr, with en being the default one.
When I switch to any language other than the default one, the translations are loaded nicely. But, then, when I switch to the third, non-default language, the translations show the default language translations briefly, until the new language file is loaded.

So en => sr-Latn => OK
So en => hr => OK
So en => sr-Latn => hr => Glitch
So en => hr => sr-Latn => Glitch

[micobarac]

Any info on this?

[DenysVuika]

needs investigation/fix