When hovering the mouse over geometry (lines, faces, components etc.), no highlighting happens and the color does not change to show the preselection.
It looks like the Quick Picking is turned off in Preferences > Selection, but this is not the case.
Right Mouse Button shows up the expected menus incl. Quick Pick and the selection works normal.
Solution
It was observed, that the 3D input device attached caused a very little movement in the 3D view, which is not visible, but recognized by NX.
Unplugging the device solved the issue.
Maybe this can help to correct this:
https://3dconnexion.com/uk/support/faq/my-3d-mouse-seems-to-drift/
Else a device defect is also possible.
Notes and References
Hardware/Software Configuration
Platform: all
OS: n/a
OS Version: n/a
Product: NX
Application: SYSENG
Version: VCURRENT
Function: SELECTION
Ref: 001-8490385