Soften edges and context menu, not working

I need to use the soften edges tool, I am doing fine with manual mode (eraser+ CTRL) but if I select the bunch of edges and use context menu soften/edge option it does nothing. Why is that? Is there any parameter I need to set before doing soo?

Soften Coplanar does something like that but it also soften edges that I don’t want. Also I am not sure if they are the same thing, they just look like similar to me.


Ok but why the context menu does not work? bug?