Here are some basic rules to keep in mind when attempting to store multi-lingual data. While storing Unicode data, the column must be of Unicode data type (char, varchar, nchar, nvarchar, etc).
Another is that the value must be prefixed with N during insertion (see below...could prove difficult in Mendix).
Insert into YourTable values (N'Your String of Chinese Chars')
Finally, verify the charset for the database is stored properly.
Storing multiple language data is tough if you don’t have access to the database or don’t write a direct query into it. I hope this at least helps guide you in the right direction.