PowerBI connector error - Unknown datatype name 'WVARCHAR'

Follow this link: How to support UTF8 encoding format?
It’s able to use unicode character, for example, select * from table_name where col1 = ‘中文’.
But in Power BI, it becomes select * from table_name where cast(col1 as wvarchar) = ‘中文’, and Dremio doesn’t support wvarchar date type.