Update Global attribute on absence record with Context attribute data using HDL?

Summary

Update Global attribute on absence record with Context attribute data using HDL?

Content

Hello

I am trying to update global attribute on absence record with Context attribute data using HDL. The issue we are facing is the category is being updated to null and attributes are also updated to null. Has anyone faced this issue and how to get around this?

Existing Data - 

Absence Entry id, ATTRIBUTE_CATEGORY, Attribute2,ATTRIBUTE11
300000027381245,300000022054551, Acne, null

HDL -

METADATA|PersonAbsenceEntry|Employer|PersonId|AbsenceType|PerAbsenceEntryId|StartDate|FLEX:ANC_PER_ABS_ENTRIES_DFF|markForRetry(ANC_PER_ABS_ENTRIES_DFF=Global Data Elements)
MERGE|PersonAbsenceEntry|XXXX|300000025177527|Sick Leave|300000027380402|2020/12/29|Global Data Elements|N