Why haven't my PDO/PLLA nose thread lifts dissolved after 2.5 years?

I got a Hiko nose thread lift in Feb 2020 and the threads haven't fully dissolved. Maybe 50%? I can feel and see it move when I push the tip of my nose up, and I still have a little dimple at the top of my nose when I make a certain face. My 2 friends and I went to the same doctor for the same procedure and theirs are completely dissolved now. I'm baffled. Can't find any answer for this online!