"Adjustable. Swipe up or down with one finger to adjust the value" is in a wrong language

An app I am developing has settings to change a language inside. To put it simple, let's assume I use my phone in German and have set the app language to English. There's a slider with the accessibility trait "adjustable". The problem is that VoiceOver reads English mixed with German using an English voice. The whole message when the slider becomes focused is something like "Your slider. Chosen value: one. Einstellbar. Zum Anpassen des Werts mit einem Finger nach oben oder unten streichen."

I tried setting accessibiltyLanguage and implementing my own gesture recognition of swipes. Nothing helped.

Do you know any solution?

VoiceOver uses system (or app) language. How do you change language ?

Note: Is it really a question about WWDC21-10121 as your tag hints ? You'll get better and faster answers with more appropriate tag.

iOS has built-in functionality in Settings for choosing a preferred language per-app. We don't recommend you try to replicate this functionality within the app itself as this makes it more challenging for system behaviours to determine the right thing.

VoiceOver itself supports multiple languages using the Languages rotor. If you are still seeing this behaviour when switching languages using the Languages Rotor, please let us know using the Feedback Assistant (and let me know the number of the issue you've filed). Thanks!

"Adjustable. Swipe up or down with one finger to adjust the value" is in a wrong language
 
 
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