Deselecting sub-objects with Ctrl deselects everything

I made a video where I try to handle subd edges but it will apply to all objects. When I ctrl+shift select sub-objects and use ctrl do deselect in my case certain edges it will deselect everything. especially with subds. It would be very nice to deselect every clicked sub-object.
As you also see in the video only a drag select will deselect certain sub-objects which is not precise.

Hi Hannes -

You need to use Ctrl+Shift also when deselecting a sub-object element.
-wim

Thank you @wim !