NX licenses will not be returned immediately after exiting NX, but after approx. 15 minutes the return takes place.
When trying to remove these licenses with lmremove, it does not work completely: the license always remains in use, it cannot be removed.
Solution
An antivirus software of Symantec Endpoint Protection (SEP) is blocking the release process. After deactivating SEP, it works fine.
Notes and References
Hardware/Software Configuration
Platform: INTEL
OS: window
OS Version: 764
Product: NX
Application: SYSTEM
Version: V9.0.3
Function: SYSTEM_TOOLS
Ref: 001-9302411