It sounds like an issue with the bulb itself. Perhaps a faulty radio or something in it.
I've had this very same issue with a couple of Sengled Classic bulbs that just for whatever reason would fall off and/or not respond at all. Once I reset and repair them, they would work for a bit and then die again within a week or two. I replaced the two bulbs and haven't had an issue since.
And side note... Damn I miss desert landscaping! LOL
Hopefully swapping the bulbs will tell me what the problem is. If it is a bulb issue, I'm not sure that I'd buy another Sengled. Might try Yeelights instead.
I've have this similar problem with Sengle Element Plus bulbs. One always works, the other doesn't work all the time, but maybe 75% like you found. I mapped it with Xbee and it showed a really low LQI of 30, vs 146 for the other bulb. Swapped position and it didn't change a thing. Showed the map to Sengled and they sent me a new bulb. Does the exact same thing 
There's a Trådfri outlet just 15 feet from it and the hub is only 25 feet from it. I'm just living with it for now. Those bulbs are in my ceiling fan so I can use them with my Luton Maestro fan/light controller and still have HE control over them. BUT, their days are limited 
Caseta Fan controller, a Pico and a double-gang plate are going to replace it soon. So then I can just use some Trådfri bulbs on the Hue Bridge.
I'm not saying to anyone "Don't buy Sengled", because lots of people like them and have absolutely no issues, and what else are you going to use if you want to connect bulbs directly to the hub without screwing up the Zigbee network? But they're not going to be on my shopping list going forward.
Same experience here with a pair of Sengleds. One started acting up after it was powered off at the wall one time, could never get it back to working properly after that despite multiple remove-repairs. Swapped it out for a new one and for now at least, I have a pair of reliable lamps in my living room controlled by a zigbee group. They are super fast and literally act as if they were wired on the same circuit.
Did you try the factory reset on it? It's a real PIA with the Sengled. I have a very tough time getting it right. I think it's power cycle 10 times quickly or something like that.
Yup. Power cycle 10 times. Took me FOREVER to get the cadence right on those bulbs.
One of the lights is not responding again....different bulb, same position. It turned on, but I can't get it to refresh it's status. Probably going to try Yeelight instead. Iris plug is 10 feet away. Granted it's through a garage door, but I feel like it should be better than that.
Got yeelights put in tonight. So far so good, and I really like how they fade from color to color instead of changing instantly. Hopefully they will work better.
Download the Hubitat app
