Just received a new Philips Hue Motion (9290012607). Enabled permission to join, pressed the setup button until the solid green light appeared and put it right next to my CC2531… nothing. 
This is my first Hue device, anyone with tips/tricks to get this thing to connect?
[Edit] NOTE: got a working zigbee2mqtt setup with several Ikea devices.
Had the same issue with a Hue Motion with the CC Stick. One of my three just never wanted to connect, no matter what.
Never resolved until a few weeks ago when I switched to a Conbee II and repaired everything. Have tried to pair the picky one as well and it paired without an issue.
Maybe luck tho…not that there should be luck in IT things.
Thanks for that confirmation, thought i was losing it 
Will get myself a Conbee II stick to see if that will work for me as well.