[Geschlossen] String translations are missing

Background of the issue:
I translated strings for over 40 subsites. After moving from staging to production, all those strings disappeared. The issue can be seen on this page: versteckter Link

Symptoms:
The apply and donate buttons should be in Hungarian, but they are in English. In the WPML string translation section, they are translated, but on the frontend, they are still showing in English.

Questions:
Why are the translated strings missing after moving from staging to production?
How can I ensure the translated strings appear correctly on the frontend?