When experiencing problems when adding IKEA devices, this is what worked for me:
0. Keep the device close (<20cm) to Homey
- Make sure the device is ON
- Add device in Homey
- When screen “add device” appears, turn OFF (2sec), ON (0,5sec), OFF (2sec), ON (0,5sec), OFF (2sec), ON (0,5sec), OFF (2sec), ON (0,5sec), OFF (2sec), ON (0,5sec), OFF (2sec), ON
- After some 4sec, the device will blink once.
- The pairing will start.
I hope this helps.