Weird problem - try either scaling or moving the vertices that are selected in this blende file:
Vertex_Bug.blend (691.4 KB)
Weird problem - try either scaling or moving the vertices that are selected in this blende file:
Vertex_Bug.blend (691.4 KB)
Yes, there is something fishy in there.
Instead of asking how did you came up with this mesh i can assure that if you export object as .obj and open and save it in Meshlab, then import back in Blender - fish are gone.
I’d suggest keeping Meshlab in some corner of your HD.
X-mirror and topology mirror are on. Latter causes the jumping, as the mesh is not symmetrical.
Yes that’s it, cheers!