We're sorry to hear about your experience with your LEDs not shutting off completely. The dimming range for LEDs varies from bulb to bulb depending on the bulb's design. That's why we engineered our LED+ (formerly called C·L) dimmers with a low-end adjustment, which allows you to adjust the dimming range of your LED bulb. For easy step by step instructions for adjusting the dimming range, please see step 7 on the following guide: https://www.lutron.com/TechnicalDocumentLibrary/0301729_Quick_Start_Caseta_In_Walldimmer_US.pdf
We also suggest making sure we've tested and approved your dimmable LED. Lutron offers a mobile-friendly web tool to help you select bulbs that work best with Lutron dimmers. To use the tool, please visit lutron.com/ledfinder.
If you have additional questions or concerns, we're happy to help. Please reach out to our Customer Satisfaction team at customersatisfaction@lutron.com, or call us 1-844-LUTRON1. We're here 24/7, so please call us any time!
Mike S. @ Lutron Support