Manual bevelling works, but not the one limited by a Vertex Group I try to bevel all the edges visible on the following picture. I select an edge and press Ctrl + G and then choose Assign to Active Group (which is named 2mmBevel). As can be seen on the picture I limit Bevel to this Vertex Group.

The problem is that it doesn't work. It did work that way for those edges that can be seen bevelled. Sometimes it worked for single edges. Sometimes I had to select several edges and assign them to Active Group together, they refused to get bevelled separately.
Anyway for this particular selected edge - once I add it to the Active Group - all other bevels disappear, like this:

The strange thing is, that when I try to bevel this edge manually it works:

What is the problem here? How can I bevel the remaining edges?
Actually, it work. May be you not assign the vertices correctly.

You should choose &quot;Assign to New Group&quot; from the Panel.

You can press &quot;select&quot; to make sure that you assign the vertices correctly.

You can assign this three vertices to bevel the remaining edges.

Disabling &quot;Clamp Overlap&quot; also can fix the problem for the questioner