I have the same issue. I connected the shelly 1L to 2 led bulbs (20 w each one) without neutral, and without bypass. Initially the shelly works great, but some switchs later the bulbs remain ON. I can hear the switch ON and OFF but louder when the bulbs really switch's the first times. Another difference is that I updated the firmware to the last version, I don't know if the problem is after the update.
If I turn OFF the switch and then Knocking it seemed to fix it and the bulbs turn off, but blinking. When I turn ON the shelly works OK and the bulbs are ON without blinking, but some time after if I turn OFF the shelly the bulbs remain ON and I need to Knocking the shelly another time. It seems a problem with heating?. And why the bulbs blink in off mode?.
Please I have two shelly 1L with the same problem. I need a solution for this.
Thanks,
Jose