Although I set the settings to “en”, parts are displayed in german. What can this be?
Is this of help? https://wiki.openmrs.org/display/docs/Localization+and+Languages
I checked it. Unfortuately, did not help.
You need to change the locale using the links at the footer of your browser as indicated on that wiki page.
Are you able to reproduce this on the demo server? https://demo.openmrs.org/