email notification translation overwriting itself

Hello,

quite often I find that an email notification, which until now was well translated into German is all of a sudden sent in English. So I go and find the string via filezilla or wPML string translation and translate it again, the email notification then comes in German, fine. Some weeks later the same email notification is again sent in English, so I again find myself translating the very same email notification.

This happens every now and then with almost every email notification and I have already spent many hours finding and translating one string three, four, five times.

One example: Email notification to client that an invoice has been created for him.

Today this Email again was sent in English. Looking into WPML translation there are now 4 strings of pretty much the same content – all translated. But still the email notification is sent in English – see screenshot ( whereas e. g. the notification email confirming receipt of data is in perfect German).

This gives me a bad feeling since I never know whether clients will receive their notifications in German or all of a sudden in English.

1. Why is this happening?
2. Where do I find the string I now have to translate since all relevant strings ARE translated already?
3. What can I do so that once a string is translated it will stay translated?
4. How can I make sure that once I have translated a string the system does not just create the same string again using the new, untranslated one?

Used Theme: surpreme directory.

Many thanks in advance
Birgit