Ctl+D will always sink boots into the ground plane. It's a well known glitch. If you select the main figure (IE: Mike3,Vic3,etc) ANY footware will sink below the lowest part of that figure because the footware remains conformed to the main figure.

If you elevate the main figure and select the footware and go Ctl+D  the footware will fall to the floor, NOT the main figure.  There is no "Smart Drop" like in Vue in Poser where groups can be dropped like one figure.  I wish there was.

I cannot save the world. Only my little piece of it. If we all act together, we can save the world.--Nelson Mandela
An  inconsistent hobgoblin is the fool of little minds
Taking "Just do it" to a whole new level!