Have you removed the LED bulbs from the equation and tested with incandescent or halogens? This will give us insight into if there is any interference stemming from the LEDs, or if the LEDs are picking up any interference from an external source.
Many people with flickering LED lights with all dimmers including Lutron RR and Caseta have used successfully used the LDS dimming products, both the LDS-E and LDS-R. Go look them up at https://ldsdimming.com/. These help with both the flickering and "wont go off" glowing problem, which is caused by small leakage current getting through the dimmer to the LED.