How to diagnose an occupancy sensor that always detects motion?
My bet: you have turned off Off-While-Occupied
Lutron occupancy sensors have what's called an Off While Occupied mode, as described in Lutron's advanced programming guide.  With this mode enabled, turning the lights off manually with the tapswitch while you are in the controlled space causes the sensor to keep them off as long as it detects occupancy.  However, if you disable this mode, turning the lights off manually with the tapswitch while you are in the controlled space turns the lights off for 30 seconds, but if you are still there once that 30 seconds is up, the occupancy sensor turns the lights back on for you.
So, following the instructions in the advanced programming guide to re-enable the Off-While-Occupied mode should fix your issue.