PWA client (macOS): The Sametime GUI should honor the user's language settings

I'm using the PWA client on macOS with my macOS language settings set to German.

As expected, I see the Sametime GUI in German language.

However, when I switch my macOS language settings to English, the Sametime GUI remains in German.

I restarted the PWA client, and also logged out of macOS and logged back in. But still I can't get the PWA client to display the Sametime GUI in English.

The client seems to be aware of the language settings, at least the app menu on the top of the screen is now in English language. Only the contents of the Sametime window are displayed in the wrong language.

In this situation, a new translation icon appeared in the window title bar (similar to this one: https://de.wikipedia.org/w/extensions/UniversalLanguageSelector/resources/images/language-base20.svg?65418). When I click this icon, it seems to offer the option to switch between German and English.

However:

a) this does not seem to work

b) I suspect that this is a browser feature, not a function of the Sametime app.

My suggestion is that the language used in the Sametime window should match the user's selected language (as long as the selected language is a language that is supported by Sametime).