shelly 1 does not switch with physical switch

Shelly 1 does not switch with physical switch, I tried to update the firmware but no luck. Current version: 20201124-091217/v1.9.0@57ac4ad8

What am I supposed to do?

Btw. wiring is ok. I am able to switch via software and also via the physical switch, but not if shelly 1 is connected.

Shelly 1 does not have any indication lights. Are you working for shelly?

It is a regular wiring, like this https://pimwiddershoven.nl/entry/automate…-1-wi-fi-module

only I use alternate switching with 2 switches.

Shelly 1 work without the switch and the switch also works without shelly. Button type: tried various settings. I think it is faulty, in the beginning for a few times it did work but then stopped working any longer.