The "Internal Mesh Gradation" of TET mesh does not work properly.
At only 10 (of 100) the mesh size is at least 4
In version 11.0 the growth is only slightly
the command that controls the variation of elements variation inside volumes has been replaced from version 11 to version 12.
The new command works in a slightly different way, in particular about values used to control the rate for dimension change.
I suggest you to check the help of NX 12.
This info is reported both in the "meshing" section and in the "what's new" section.
You can even read it from the link that I add below, for your comfort: