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

I don't know if this will help in your case, but simon contact, for example, offers a so-called "flare eliminator" - WKSL. This is used in situations where, for example, there is a backlight in the switch and the bulb still glows when the switch is turned off. This element is a resistor and capacitor.

>>21390425 I was impatient and on a trial basis bought the first better one available in the market - it was called the 'KS-1 illuminated switch capacitor for led lighting' from Abex. This item differs from the proposed WKSL from Simon in that it only contains a 0.1 uF capacitor, no resistor. Nevertheless, it works - connected between N and S1 of the Zigbee relay.

Problem solved, thanks a lot for your help!

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

However, I have a question for electricians.
On allegro I see a whole lot of offers under the heading 'LED FLASH ELIMINATOR WKSL CONDENSATOR'. There are also more powerful capacitors, e.g. 220nF, and eliminators described as a capacitor + resistor (for example 0.1 uF + 110 kOhm). Could someone please explain to me in an accessible way what the disadvantages/benefits of certain solutions are?
Leaving aside the main topic, i.e. the non-compatibility of the illuminated switch with smart-home modules, but also as regards the elimination of the flare/flicker/residual light of some LED bulbs when the switch is switched off.