Do fillers change shape slightly over time?

While looking into fillers, I became just as curious as I was about how the shape changes over time.

I liked it at first, but I was wondering if the process of the volume decreasing over time is natural, and if it is possible for one side to look different.

I am especially cautious because I think even small changes would bother me, particularly with a part of my body I see every day like my face.

For those of you who have maintained fillers for a long time, did the feeling differ significantly between when you first had the procedure and a few months later?