Empty Synonyms list in Find UI

I'm having a problem with the synonyms list in Find UI. When adding a synonym, i get a message that the synonym is saved and the response is something like this:

{"status":"ok","id":"2Bvbv-2iS5u6S5tAlhtsmQ"}

But the list doesn't update. Reloading the ui does not help. Still an empty list. Any suggestions?

Find version is 11.1.4.4296 

Regards

Patric