Winget installing wrong locale version of app

Brief description of your issue

Winget is installing packages using the wrong locale. I tried to install Mozilla.Firefox, which within the package specifies en-US as default and my system is also set to en-US, however winget installed the en-GB version of it even on a 2nd and 3rd try.

I just freshly installed windows 11 23H2 (after updates OS Build 22631.3007) using the en-US iso (Windows automagically set the country or region in settings to Germany regardless of my choices, but that's not an winget related issue). I also didn't log into Microsoft account and installed it using a local account (as connecting to the wifi didn't work, even though it was detected on the oobe screen, so it cannot be something fetched from there either).

For reference, I did not change any of the localization settings manually (yet) and my system has:

PS C:\Users\user> Get-WinUserLanguageList


LanguageTag     : en-DE
Autonym         : English (Germany)
EnglishName     : English
LocalizedName   : English (Germany)
ScriptName      : Latin
InputMethodTips : {}
Spellchecking   : True
Handwriting     : False

LanguageTag     : en-US
Autonym         : English (United States)
EnglishName     : English
LocalizedName   : English (United States)
ScriptName      : Latin
InputMethodTips : {0409:00000409}
Spellchecking   : True
Handwriting     : False

LanguageTag     : en-GB
Autonym         : English (United Kingdom)
EnglishName     : English
LocalizedName   : English (United Kingdom)
ScriptName      : Latin
InputMethodTips : {0809:00000407}
Spellchecking   : True
Handwriting     : False

PS C:\Users\user> Get-WinHomeLocation

GeoId HomeLocation
----- ------------
   94 Germany

Steps to reproduce

1. Be in Germany
2. Install Windows 11 Pro 23H2 using the en-US iso and the default locale settings for en-US.
3. Let windows install all updates.
4. winget install Mozilla.Firefox

Edit: Issue is caused by the presence of "en-DE" (why is it even there when I freshly installed en-US Windows?) within the WinUserLanguageList. When I order en-US before it winget is correctly installing en-US. However even though it has higher priority than en-GB (as seen above), when en-DE is listed first, en-US 2nd, and en-GB 3rd winget still defaults to en-GB. (Same, but expected, for en-US being 3rd and en-GB 2nd).

Expected behavior

Installing Mozilla.Firefox using the en-US locale

Actual behavior

Installing Mozilla.Firefox using the en-GB locale

Environment

PS C:\Users\user> winget --info
Windows Package Manager v1.6.3482
Copyright (c) Microsoft Corporation. All rights reserved.

Windows: Windows.Desktop v10.0.22631.3007
System Architecture: X64
Package: Microsoft.DesktopAppInstaller v1.21.3482.0

Winget Directories
-------------------------------------------------------------------------------------------------------------------------------
Logs                               %LOCALAPPDATA%\Packages\Microsoft.DesktopAppInstaller_8wekyb3d8bbwe\LocalState\DiagOutputDir
User Settings                      %LOCALAPPDATA%\Packages\Microsoft.DesktopAppInstaller_8wekyb3d8bbwe\LocalState\settings.json
Portable Links Directory (User)    %LOCALAPPDATA%\Microsoft\WinGet\Links
Portable Links Directory (Machine) C:\Program Files\WinGet\Links
Portable Package Root (User)       %LOCALAPPDATA%\Microsoft\WinGet\Packages
Portable Package Root              C:\Program Files\WinGet\Packages
Portable Package Root (x86)        C:\Program Files (x86)\WinGet\Packages
Installer Downloads                %USERPROFILE%\Downloads

Links
---------------------------------------------------------------------------
Privacy Statement   https://aka.ms/winget-privacy
License Agreement   https://aka.ms/winget-license
Third Party Notices https://aka.ms/winget-3rdPartyNotice
Homepage            https://aka.ms/winget
Windows Store Terms https://www.microsoft.com/en-us/storedocs/terms-of-sale

Admin Setting                             State
--------------------------------------------------
LocalManifestFiles                        Disabled
BypassCertificatePinningForMicrosoftStore Disabled
InstallerHashOverride                     Disabled
LocalArchiveMalwareScanOverride           Disabled

Start by reproducing winget install Mozilla.Firefox with the listed Windows language order, then trace how the CLI selects a package locale from WinUserLanguageList. Check the behavior when en-DE precedes en-US and en-GB; done means the en-US package is selected when it is the preferred matching locale, without breaking expected fallback behavior.