In the Philippines every government employee makes their own rules, so the answer to the "why" question is mostly "because".
For years I had my "I'm still alive" document (for my pension fund back in the Netherlands) signed and stamped at City Hall with no problem whatsoever, but when the city lawyer who was my go to person for that matter retired, his successor suddenly wanted me to get "barangay clearance" first before she would sign and stamp my document.
Why? Because.