Appointment Hour Booking translation

Hello!

I’m trying to translate Appointment Hour Booking plugin with WP-Multilang. I’ve followed the tutorials and added the id to wpm-config.json and languages’ tabs are shown(English and Greek tabs)

The problem I have now, is that when I translate a service on English, field overrides the other language (Greek) and vice versa.
Translation works if I use [:en][:el] tags, but this method is not user friendly, as on the next save, override happens again.

How can I prevent that?

Thank you in advance