Simon 55 Zigbee Switch Integration: Illuminated Button Causes 66V in Off State?

Good morning,

I have a problem integrating a Zigbee module with a Simon 55 illuminated switch.

I have 2 different Zigbee modules from the light switches - an OXT and a straight from China GIRIER Tuya ZigBee 3.0 - externally, to be honest, they look identical.

When I had the connectors themselves fitted to the bulb - everything worked as expected.

When I connected the Zigbee module - I could only control the on/off via the Tuya app. The physical button didn't change state, as if it was still on.

I went to my senses and measured the voltages with a meter. It turned out that the illuminated switch in the on position was giving an alternating voltage of 230 volts, but in the off position it was still generating a voltage of about 66 volts. The bulb did not light up, but when I changed the light source to a GU9 LED attached to the lamp I bought, it turned out that on the switch alone (without the smarthome module) in the on position the bulb shines brightly, in the off position much less, but still. I should add that the Zigbee modules claimed to be compatible with 110-230 volts, but yet when 66 volts was applied it still saw an 'ON' state.

Do you know of any solution to the problem?
- another Zigbee module
- solder something in the circuit to reduce the voltage when in the off state, but so that the backlight in the physical button still works?

Regarding the connection - according to the attached file

>>21390425 I was impatient, so I bought the first one I could find in the supermarket on a trial basis – it was called the ‘KS-1 backlit switch capacitor for LED lighting’ by Abex. This component differs from the WKSL model offered by Simon in that it contains only a 0.1 µF capacitor, with no resistor. Nevertheless, it works – connected between N and S1 of the Zigbee relay.

Problem solved, many thanks for your help!

The solution is a capacitor connected in parallel to the Zigbee module between the N and S1 inputs (the output from the physical switch). Specifically, I used a 0.1 µF capacitor rated for 275 V.

However, I have a question for electricians.
On Allegro, I can see a whole host of listings under the heading ‘WKSL LED FLICKER ELIMINATOR CAPACITOR’. There are also higher-capacity capacitors, e.g. 220 nF, as well as eliminators described as a capacitor + resistor (for example, 0.1 µF + 110 kOhm). Could someone explain to me in simple terms what the pros and cons of these different solutions are?
Leaving aside the main issue – namely, the lack of compatibility between the backlit switch and smart home modules – I’m also interested in the elimination of flickering, flashing or afterglow in certain LED bulbs when the switch is turned off.