It should not run for the given time duration.It should stop . But it shows stopping until the given time duration is complete.
If you have configured your variable to stop the test when running out of values then the test should stop. Make sure that stop policy is immediate.
Then look at the NeoLoad log files and load generator logs files, there's maybe an error that may explain why the test does not stop.
Does it happen all the time for any project?
Which NeoLoad version do you use?