Issue in Customize Clearance check list under the People Management form

 Dear 

We are on 11.5.10, we have created NEW template as "EXIT CHECK LIST" of People management, in which we have configured our own list which are mentioned below as example.

Check List
Name                             Date                         Status as List value

IT Department              user_input manually Verified/Pending
Finance                        user_input manually Verified/Pending
Human Resource           user_input manually Verified/Pending

Now issue is, when head of above department change their corresponding record and successfully being update but system update last_updated_by column in all above three records who perform update/change record very last although he updated only IT record.

Therefore, we are not able to get their concern department Name in last updated by due to this issue.