I'm not sure when this started happening, but it feels like a fairly recent problem. Very simply, if you add a PB Object to a scene (let's say, a PB Cube), then using the Face/Edge/Vert tools to adjust its shape, the PB Object's mesh collider will NOT update to reflect the new mesh. It will instead continue to have its original collider bounds, such as the cube it started out as. I've recorded a short video showing this in detail: There are a couple of annoying impacts to this bug. First, when dragging objects (like prefabs) into a scene, they don't snap to the PB objects. Normally dragging a prefab over an object in the scene view will place the new object physically on the old one. But with PB objects, they just go through the object. Another issue is that any gizmos that use raycasting to detect geometry don't work properly. There's a gizmo on an HDRP point light, which drops a green line from the light to the first thing it hits below the light. Moving the light over the PB object will not show the drop-line when the light is over the "new" portion of the PB object. The (bad/temporary) workaround for this is simply to the PB object, or just the collider, and reenable it. But if you continue to modify the PB object, it will once again be out of synch with the renderer. Reported as bug #1283167.