Can't calibrate LED bulb

I have a Shelly Dimmer 2 that has been connected to a halogen 70W bulb and been working fine. I tried connecting a new 9W LED dimmable bulb, but when I calibrate it, it gets to 13% and then the bulb starts flickering and the dimmer2 loses power every time so it can't complete.

I set it to Leading Edge and it managed to calibrate but then every time I switch it on it turns off after about 5 seconds and the webpage says "wrong calibration".

I think it's sending too much power and overloading the bulb, though I am far from an expert. Is there a way I can manually calibrate or some settings to try? I fiddled with debounce settings but I don't really know what I'm doing, none of my other dimmers are attached to LEDs.

Thanks in advance!

Misha

Ah, there's no neutral wire, that must be the issue - thanks for your help!