Did you make sure to switch the HUD profile you want to edit before going to the HUD settings?
The setup you did should apply to the HUD you currently have in display in your HUD creator. After saving the HUD profile, just reload/re-select the HUD in your table and it should apply your new sample size settings.
If you are still having an issue with the sample size setting, please send the HUD profile to our support email so we can check this for you.