Application sometimes chooses wrong language, when using local versions of language

Description

When the user changes the application language from English to another language and then switches back to English, the application UI remains displayed in Slovak instead of reverting to English. The issue is reproducible on both Android and iOS platforms. After restarting the application, the issue still persists.

Environment

STAGING

Application:

Device/OS/APP: Samsung Galaxy A53 / Android 15 / 2026.3.0 - 818251
Device/OS/APP: IPhone 15 / iOS 26.5 / 26.6.912411

Steps to Reproduce

1. Open the Mergin Maps mobile app.
2. Navigate to Settings.
3. Verify the current language is set to English.
4. Change the language to any language other than English (e.g. German).
5. Confirm the language change. Verify the app UI switches to the selected language.
6. Navigate back to Settings.
7. Change the language back to English.
8. Confirm the language change.
9. Observe the application UI language.

Actual Result

After switching back to English, the application UI displayed in Slovak language instead of English. The language setting appears to revert to Slovak regardless of the user's selection.

Expected Result

After switching back to English, the application UI is fully displayed in English.

Attachments

Screen recording showing the language switch sequence and the incorrect Slovak UI displayed after switching back to English (iOS).

https://github.com/user-attachments/assets/3df74f82-9986-4e54-9c6a-557b87465a14

Screen recording showing the same behavior on Android

https://github.com/user-attachments/assets/bb5a5e56-a197-43d0-b812-44e3865f2ea2