Date format unexpectedly reverting to default

[overitola]

Hi!

A newbie here with a question regarding strange behaviour with the date format in OTRS 5.0.14. We're using English as the only language for OTRS but have edited the en.pm file to get the date in European format (dd.mm.yyyy). This works for a while but sometimes after a couple of minutes and sometimes after several days the system automatically starts displaying the date again in the default en-format (mm/dd/yyyy). After I open the en.pm file and save it, the preferred European format is once again applied but again after a while the systems reverts to the unwanted default English format.

Any idea what's going on here and how to stop this from happening?

All the best,
Ove