sorry I didn't get the fact that you use NX11. NX10 should behave as you expected it.
As Ben mentioned, this is working as designed, and there are also upsides to this new behavior.
Objects are now highlighted during Rectangle drag. You can now see what your rectangle selection will include before you finish it.
as Ben and I mentioned before, there are changes in the way NX11 rectangle selection works.
If you feel that this slight delay is a problem, you can contact GTAC. But I am afraid that they may not create a Problem Report for you.
Mine behaves the same way, K4000 Quadro, the problem is that while its detecting what to display it locks up the screen momentarily, then once it highlights, it releases and you can move the rectangle again, if you hesitate slightly it locks up the screen while it calculates what to show for selection. If I try and carry on with my rectangle while locked up, the curser moves off the rectangle, then when it finally selects it jumps right away back to the curser---a little annoying
that's why I don't use the Lasso option, it slows me down too much waiting on it.
I can select faces faster individually or small rectangles.
Elmhirst Industries, Specializing in Prototype sheet metal stampings and assemblies
Production: NX 12.0.2 / Autoform r8 /WorkNC 2020.0
PC: Rave Cadbeast: Intel(R) i7-4790K CPU @ 4.GHz /32gb ram /NVIDIA Quadro P2000 on Win10 Pro