Well, apparently the room behind the switch on the first floor isn’t enough to fit a Shelly behind.
So I decided to install the shelly above the lamp, the welding box is also above the lamp self.
I followed this schema what was designed for a hotel swtich:
This is my setup how the switching is working, the lines behind the switches only go through the mount box were the switch is installed in:
This is how I installed it now:
I thought I understand how it worked and that this was the right way but the light wont power on, even though the switch is on, it is flashed with tasmota and connected to my router.
The sehlly is powered on so I can reach his IP address, when I toggle it in the web page, the light also wont turn on.
I also discovered when the light switch is off on the ground floor, you can’t toggle it on the first floor, but if it is set to on, then you can toggle it…
I’m really cracking my head on it, but can’t figure out what to do, who can help me out?