It seams to have the same logical problem as geocoder-php/Geocoder#408 (comment), but don't know yet how reset locale after use geocode

$result = $geocoder->using('cache')->geocode('Paris 15, France'); //Locale NULL
$result = $geocoder->using('cache')->setLocale('de_DE')->geocode('Paris 15, France'); //Use locale de_DE
$result = $geocoder->using('cache')->geocode('Paris 15, France'); //Use locale de_DE

or maybe add after $data = $this->provider->geocode($address);

if (null !== $this->getLocale() && $provider instanceof LocaleAwareProvider) {
    $this->provider->setLocale(null);
}

But seams uggly

poke @Baachi

As i said in the linked PR, I'm not a big fan of it, because it will lead to errors and the symfony/dependency-injection made it very simple to build different providers.

Anyways, here another approach:

We can extend the addProvider method and accept that locale can be an array. If the locale parameter is an array, build x Providers and change the name to: <myname_<local>.

This would looks like this:

bazinga_geocoder:
    providers:
        google_maps:
            locale: [de_DE, en_US, ru_RU]

and in the controller you can now use:

$this->geocoder->using('geocoder_deDE')->geocode('Alexander Platz, Berlin');