Last Modified Date and Last Modified By fields
|Knowledge Article Number||000005055|
Organizations with the "Create Audit Fields" permission enabled may fail to update the Last Modified Date and Last Modified By fields.
Last Modified fields may not be getting set with inserted values because there are triggers on the object. If those triggers update the record, new Last Modified values will be used rather than the provided values. If the audit fields must be populated using the provided values, one workaround is to disable triggers.