Rhino 6, Solid manipulation, extrusion

Hello, I am a beginner, (also for posting…) I test solid manipulation without exploding it, using the gumball (or not…). I splited one face and tried to extrude
when I extrude out of the solid,it looks ok
but if I want to reduce the volume, only the face move.
If I check the proprieties, It is still a “closed solid polysurface”
Obviusly, it is not and it not what I expect, I’ll like to push the full bloc

Unfortunately you can’t do this currently with the Gumball extrude handle but you can get the result you want by using the command _ExtrudeSrf on the surface you want to push, with the option _DeleteInput set to _Yes.

Thanks a lot. I’ll try ASAP.
something wrong with the gumball?

sorry but I have the same result

wait…I thing I exploded sorry, I try again from scratch

geneallly speaking, I test working on architectural massing into Rhino.
For massing studies, I start always with a “box” and I play with the volume, pushing and pulling some parts. I always did that in much simpler 3d softwares.
Is it the best process for Rhino? Starting with a the box, then split faces and moving them? thanks for the advice.