Unable to add new grade to employment info, through Position HSDL

We are uploading new Valid grades to the position, through Position HSDL. It ran successfully, old valid grades were removed and new were added.

Then we checked employment info page and found that Grade field is populated with old value. Checked Employment history and found that no new record is created.

We did one transaction through front end. We added new valid grade on position through front end, and removed old one and submitted the transaction. It was successful. Now when we checked the employment info page we found that grade filed is populated with new valid grade, and there is new record created in Employment history with action - Synchronization from Position.