An issue has been reported where BulkInsert-Task doesn't insert decimal values correctly.
The issue occured when user mapped a JArray data which contains a decimal value, such as 2.37.
When the data was inserted, the value turned to 2.36.
When we switched the Task to ExecuteQuery, and set the fields data type to decimal, the insert worked correctly.
So it would seem that inserts to Decimal-type fields are not working correctly with BulkInsert.