Failing to control 31V LED fairy lights using a Zigbee Switch

Hi there,
I’ve got a classic Christmas problem:
My wife ordered some Christmas fairy lights for our garden (, which I want to control using Osram Zigbee Switches ( or

But I fail:

  • I start with the lights turned on
  • I turn the lights off, no Problem
  • I want to turn the lights on
  • If I’m lucky, the lights turn on (30% of the time)
  • If I’m not lucky, the lights don’t turn back on
  • When the lights don’t respond I can do Whatever I want, they won’t come back until I manually disconect them from power.

I’ve tried many different configurations, my my preferred solution would be using the Outdoor Switch directly at the power outlet and then using an extension cord (~15m) to connect to the fairy lights.