Help: Fibaro FGS-222 Dual Relay physical switch keeps switching between on and off


I’ve set up a few of the Fibaro FGS-222 Dual Relay switch around my house. I realise there is a common problem among them, when i use the physical switch on the wall, it keeps switching on and off. Sometimes it stops sometimes it doesn’t, I just have to wait and press on my wall switch again. I could hear the ticking sound from the fibaro switch. This only happens for the ‘second’ switch of the relay. The first switch is fine. Everything also works fine on the phone app for both first and second switch.
I tried reseting it by cutting the power from my circuit breaker, moving my hub, the problem still persists.

Is there anything that i might have missed out or could rectify? A bit of a stuck here. Thanks in advance for any input!

I set up the switch following this very useful guide:

another point to note is that the ‘second’ switch works fine when operating with the physical wall switch while the relay is not online. Its only when it goes online then it starts to get cranky.