How to select components through the Transform Gizmo? I have Blender installed on 2 PC's. On PC (a) if I go into component mode and have the transform gizmo visible, I can select a vert and then individually select the neighbouring verts through the transform gizmo. The gizmo does not block selections...    on PC (b) however, I cannot do this. It will instead try to trackball rotate the first selected component, even though I am not dragging the mouse, but stationary clicking. The transform gizmo is blocking the selection. 

I have compared, by eye, all the preferences etc and they are identical.  Is there an option or a toggle somewhere that would cause this behaviour? being able to select through the gizmo is pretty necessary for me.
In the Keymap Preferences there is the option Activate Gizmo...   this needs to be set to Drag and not Press. 

However, it seems there is a bug that can make this entire preferences section disappear from the Ketmap preferences.