Pydio sharing page is not displaying the default language, how to fix it?

I’ve the Pydio 8.2.5 (2020-01-07)
(Running on Ubuntu 18.04.4 LTS, Apache 2.4.29, PHP CLI 5.6. Pydio has been upgraded for the last 3 years.)

The default language for unknown user is English (Application Core Setting / Pydio Main Options).
But sharing a public URL the page is German. (The text for “download”, “open with” is German :frowning: )
I’ve change the browser language also, but it didn’t help.
I tried to change the Pydio default language to Spanish but it didn’t have any effect.

What can I do?

ps. Adding a language parameter like: does not work, it still German :frowning: