Android API>33 set locale from device settings + black screen

Question

In my android app I am trying to implement the in app language with a new way (for API>=33 and backwards compatibility).

I also created xml config file, added things to manifest, etc, but this is the code itself:

lng = Resources.getSystem().getConfiguration().getLocales().get(0).getLanguage();
    LocaleListCompat appLocale = LocaleListCompat.forLanguageTags(lng);

            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.UPSIDE_DOWN_CAKE) {
                overrideActivityTransition(Activity.OVERRIDE_TRANSITION_OPEN,0,0);
            } else {
                overridePendingTransition(0, 0);
            }
            AppCompatDelegate.setApplicationLocales(appLocale);

So when the app starts, it takes device language and set the app language.

Then also switching in app languages works fine.

Question 1: For API>=33, the user can select app language in Device System -> App language.

How to obtain this value?

Question 2: AppCompatDelegate.setApplicationLocales(appLocale) also restarts the activity and I noticed a black screen during this (I tried on emulator with APi33, did not notice on real device with API 32).

For that reason I used overridePendingTransition (it is deprecated for API>=34, that's why I used this condition, but it doesn't matter now):

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.UPSIDE_DOWN_CAKE) {
            overrideActivityTransition(Activity.OVERRIDE_TRANSITION_OPEN,0,0);
        } else {
            overridePendingTransition(0, 0);
        }

This however doesn't help.