I have recently started using openHAB and just installed a number of cree connected bulbs yesterday. The bulbs are connected directly to openHAB through an Ember zwave/zigbee adapter and paired without issue.
I created a Dimmable type item for each bulb in an items file and have added tagging for HomeKit. Through PaperUI I connected each bulb with an item and at first glance thought everything was working perfectly through both the openHAB UI and HomeKit. Once it got dark and I turned bulbs off however I noticed that the lights were not actually off but maintained a very low dimness level. While the light at this level is essentially unnoticeable, the bulb is still on. After some reading I am thinking I might need to add a switch item to each bulb but am not sure if that is going to work given the bulbs are only presenting a Level Control channel to openHAB. As a quick test I added a switch item in PaperUI and connected it to the Level Control channel of one bulb and while it did control the light, the bulb remained in the same state as before when it was dimmed to 0%. This behavior was common between three bulbs.
From what I can tell, adding a switch should resolve this problem but I think the switch needs to be connected to an On/Off channel to send the right command (maybe I am wrong). The only other thing I can think to do is to reset each bulb and try pairing them again. If someone could point me in the right direction I would really appreciate it.