Android and iOS Application's language does not match

I have implemented the localize plugin, and Im' facing issues:

"get the default language on user's phone via the language property of the Device class."

I have Android which phone language setting is set United Kingdom (en) this picks up correctly. On iOS I also have the setting language to English as preferred language but this isn't printing correctly. I the following code.

    console.log('DEVICE LANGUAGE', device.language);
    console.log('From Cores, Device.language);
    console.log('from __app__language__', ApplicationSettings.getString('__app__language__'))
    const localeOverriddenSuccessfully = overrideLocale(Device.language); 

On Android is correct:

On iOS is incorrect:

ns --version
8.5.3
✔ Up to date.

Angular:
ng version

 _                      _                 ____ _     ___
/ \   _ __   __ _ _   _| | __ _ _ __     / ___| |   |_ _|

/ △ \ | '_ \ / | | | | |/ _ | '__| | | | | | |
/ ___ | | | | (| | || | | (| | | | || | | |
// __| ||_, |_,||_,|| _|||
|___/

Angular CLI: 15.2.8
Node: 20.4.0 (Unsupported)
Package Manager: npm 9.7.2
OS: darwin x64

Angular: 15.1.5
... animations, common, compiler, compiler-cli, core, forms
... platform-browser, platform-browser-dynamic, router

Package Version

@angular-devkit/architect 0.1501.6
@angular-devkit/build-angular 15.1.6
@angular-devkit/core 15.1.6
@angular-devkit/schematics 15.2.8
@angular/cli 15.2.8
@ngtools/webpack 15.1.6
@schematics/angular 15.2.8
rxjs 7.6.0
typescript 4.8.4

=============================================
It seems to me that on iOS some how it cached into the the phone's default language variables, earlier on I was manually updating the language like so:
const localeOverriddenSuccessfully = overrideLocale('nl');
could this have been cached for iOS on this variables prior?

device.language
Device.language
__app__language__

Thanks

Start by reproducing the discrepancy on Android and iOS using the shown Device.language, device.language, ApplicationSettings.getString('app__language'), and overrideLocale calls. Compare the returned values after changing the device language and after manually overriding the locale; done means the cause is identified and the issue's expected iOS behavior is fixed or clearly documented.