how do I stop blender from randomly creating multiple (often disconnected) vertexs in the same place? ver 2.82a While trying to create a low poly standing model I keep finding (while loop subdividing or while grabbing individual vertexes) a face has been lifted off with two (often) disconnected vertexes overlapping the same spot. The model seems to keep doing this in spots I'm not working on even.

I'm not sure, is this a bug?
Go to mesh > clean up > merge by distance... figured it out but any idea why it happens?