Bulk Import: Cannot bulk update a non-controlled attribute on an approved, change controlled Document object


I'm on v15.4.1.325 HF 342 and trying to use the Bulk Import tool to update the value for a mandatory, non-controlled, fixed attribute on Document objects that already exist in eB. The attribute value updates for all not approved Documents and for approved non-Change Controlled Documents. But the import rejects the attempted update to approved Change Controlled Documents. However, I can navigate to the approved, change controlled Document in eB Web and update the attribute. Is this a bug? Is there a workaround? Also bulk updating the attribute in Director is not an option. The rejected log reads:

Output Row No:: 4 in Filename: 527201541912PM.xlsx
Document Prefix::AD-2011-LOC-000001
Document Middle::
Document Revision::000
Given document is already approved and changes are not allowed
Document Is Rejected