Absence Validation FF not working from HDL

Summary

Wrote an absence validation FF and attached to absence Type. Working correctly in UI, but not HDL

Content

Hi All,

 I wrote a validation Fast Formula and attached to absence type. I used a Value set in that FF. The value set contains logic based on the logged in user (and pu.user_guid = FND_GLOBAL.USER_GUID),  as my business requirements demands so. 

This is perfectly working fine when I enter absences from application UI. However, when I try to run the HDL from the same user, it is not working as expected. The 'FND_GLOBAL.USER_GUID