Some static pages don't show anymore

Dear Support Team,

I have a new issue, which was not existent before (although I have been using mqtranslate for a while – unfortunately I can’t remember the changing event): my website https://www.little-hamburgers.de shows all nicely in Englich language but does not in German langugae. Further, the log-in on the English pages does not work properly.
Can you help?
Kind regards
Kerstin

https://www.ads-software.com/plugins/mqtranslate/