HCM PVO extract numeric data type content column contents characters

The HCM PVO extract within BICC for numeric data type column contents characters in the extract result.
During our extract offering creation and job setup, no additional change was made.

The offending data object was: the BUSINESS_GROUP_ID - from Oracle documentations this field should be numeric only. but during extract, which contents letters such as "HR", "Manager", etc.

Upon reviewing via query in BI publisher, no other data type was found but only "1" (as data record) exists in the system.

Please for your advise. Thanks