Chin filler moved after eating. Is this normal? I had Voluma injected in my chin about three weeks ago.

A few days ago I was biting an apple and the filler suddenly shifted, it felt very strange similar to a numbing sensation. I looked in the mirror and it had moved towards my lips. I got horrified and massaged it before calling my doctor and hopefully it went back to its place but I’m worried it would happen again. Also when eating I can see the “shape” of the area injected which doesn’t look gradually faded with the rest of the skin.