Aeotec ZW150 Nano Dimmer Bypass Load Resistor and Dummy Load for Dimmer TRIAC Dimmer Switches to Fix Flicker Problems - Black

If the no neutral smart switch still lights the LED fixture when off, you might be able to install a bypass in parallel with the light fixture between the switch leg and neutral (at the light location). They can range between $5-$20 (USD) depending on where you buy them, but likely shipping is going to cost almost as much as the bypass unless you can find one with free shipping like on Amazon or something. EDIT: Example of what I am referring to... https://www.amazon.com/ZW150-Resistor-Switches-Flicker-Problems/dp/B017BK1MIA