Shelley mini 1 gen3 contact stuck

[devilzeyez]

I have Shelley mini 1 gen3, connected to a light and small fan, when i open the door it swithes on to turn on the light and the fan. If the lights keeps on for like more than 15 min, the shelly device stoppes working, i have to knock on it to work again, its like that the contact inside is stuck. I thought the device is defect and change it to another one but the same problem happens again.

[thgoebel]

Obviously, the contacts adhere due to (a) high inrush current (is is a LED lamp?) or (b) high voltage transients at the moment the fan is turned off.  What wattages does the lamp and the fan have? Either an inrush current limiter or a RC snubber could give a remedy.