Sculpting noob here, does anybody know why some of the mesh on the other side of nose doesnt move?

Im jusing the mirroring but I didnt created this mesh. I trying to make the nose bit smaller but for some reason it doesnt move all of it, just some faces, I dont know if it has to do something with red lines which I also dont know what they are. If somebody knows thank you for your time

https://preview.redd.it/lzrf48a3b22e1.png?width=1588&format=png&auto=webp&s=677337dfd3e16ccc0bf908e44fc2e7e375f9486c