I just updated the Bulb FAQ, but I’m going to go ahead and post to duplicate of that message here to make sure that the OP sees it:
An update for Fall 2017: Zigbee Bulbs that Can Lose Messages from Your Other Devices
Over the last year, a number of network problems have been reviewed by both community members and SmartThings staff, and it’s now been established that some, but not all, zigbee lightbulbs when connected directly to the SmartThings hub Will be marked by the network as available repeaters, but will in fact failed to pass on some messages from some of your other zigbee devices. 
This can make it seem, for example, like an open/close sensor is failing to report when in fact it is reporting, but the bulb is not passing the message on.
This is an extremely annoying problem and one that is difficult to diagnose if you run into it.
Avoiding the problem by choosing the right brands
If you are connecting your zigbee bulbs to the hue bridge, you won’t have this problem, because the bridge forms its own mini network and your other zigbee devices will not even know that the bulbs exist. Note that this is also the only officially supported method for Hue bulbs:
But if you are connecting the zigbee bulbs directly to the SmartThings hub, the following brands are known to have problems in this regard as of January 2019:
GE Link
Hue if connected directly to the SmartThings hub
IKEA Tradfri
Osram/Sylvania
Cree Connected if you have more than 10 bulbs
Brands that don’t have this problem as of October 2017:
Cree Connected if you have 10 or fewer bulbs
Sengled (these won’t lose messages, but they won’t act as repeaters either)
IKEA Tradfri as of mid 2018
Anything connected to the Hue bridge
I was going to recommend the cree, but then @KevinH reminded me that these bulbs still have a problem with routing if you have more than 10 of them. So now I recommend IKEA Tradfri. Just make sure you get current ones as the original models had different firmware. As of January 2019 The IKEA Tradfri bulbs and pocket socket work with SmartThings: the handheld remotes do not.
other protocols
Zwave Bulbs and WiFi bulbs don’t have these issues, and in fact, in general zwave bulbs make very good Z wave repeaters. It’s just zigbee bulbs that have shown the problem.
if you already have problematic bulbs
There is a workaround, but it’s really annoying.
If you were going to add a new zigbee device to your network and you want to make sure it doesn’t try to use one of the problematic bulbs as its parent, first take any of the problematic bulbs off power all together. Not just turned off from the network, but actually switched off current.
Now add your new device. It should choose one of your other zigbee devices as its parent and its messages won’t get lost.
Then turn the bulbs back on power.
Also be aware that if at any time your house loses power, you may have to repeat this method or your other zigbee devices might select a problematic bulb as a parent when the power is restored.
I personally like Hue bulbs connected to the hue bridge and that’s what I use at my house.
You can go ahead and try any of the other brands, but if you start having problems with other zigbee devices appearing to lose messages, run a test by taking all the bulbs off power first, then do a zigbee heal, and see if anything improves. It may be the bulbs are receiving the messages but not passing them on. 
If you are coming to this thread after October 2017, check the bulb FAQ for the most up-to-date information: