Weird mix of language in mail app

[CarlSchwan]

Expected behavior

Only french appears on the UI elements since it the language I choose in nextcloud to use :)

Actual behavior

A mix between French and German. See screenshot

Mail app

Nextcloud 22 (company instance)

Client configuration

Browser: Firefox 93 configured to get english version of pages
Operating system: openSUSE tumbleweed

[ChristophWurst]

locale vs language? ref nextcloud/server#14784 and its friends

[CarlSchwan]

Yes this is that bug.