MDM Java API 2 - update of qualifier fields

Hi

since I updated to the latest Patch SP5 Patch 2 of the MDM Java API, I cannot update any qualifier field values.

This is what I do:

QualifiedLookupValue qlv = (QualifiedLookupValue) record.getFieldValue(FIELD_ID_CATALOG);

qlv.setQualifierFieldValue(index, someFieldId, new IntegerField(someInt));

record.setFieldValue(FIELD_ID_CATALOG, qlv);

The ModifyRecordCommand then shows up with an exception: "com.sap.mdm.internal.protocol.manual.ServerException: Das Feld kann nicht bearbeitet werden" (The field cannot be modified, ErrorCode: -5631993, RC_CM_FIELDNOTEDITABLE).

Before I made the update, the update worked as expected. Has there been a conceptual change of how this must be done? Or is this just a bug?

Please help! Thank you