To enable continuous screening, mark Auto-repeat (AR) Scan/Explore option and enter the repeat interval. The interval can be specified in minutes or seconds (for example entering 10s means 10-seconds, while 5m means 5-minutes).
Yup ,Hitting the ENTER key ,as Milosz said ,will set the Auto Run Scan Interval.
Also you can customize the AR button ,Remove Text to save some Real Estate And the Button will appear highlighted if Auto Scan is Running.
“Hit Enter” was the solution. I spent 2 hours because I was clicking away or I was hitting the TAB button. I was afraid to hit Enter on a menu item.