I feel your pain. I moved most of my home automation over to other controllers after our front door lock began randomly unlocking back in November. Support looked at this as did SmartThings engineers, and although they verified it was happening, no one could figure it out. My personal guess is that it had to do with synchronization between the cloud and the V2 hub, but I’m not sure.
We had had SmartThings for about a year prior. I am mostly homebound and spend much of my time in one of two rooms, the one where the lock is and the one next to it. In addition, my service dog is trained to go to the door when it unlocks. So I’m pretty sure this didn’t used to happen as one of the two of us would’ve noticed. But it did happen at least five times in one week in November 2015. At different times of day.
I continue to see this type of behavior on some of the night lights that we have left on SmartThings. You can see it in the logs.
The following thread is by an engineer who has identified one synchronization problem. This might well have been the cause of what I was seeing.
Or it may have been some kind of database corruption and my house was receiving commands intended for someone else’s account. It was right about this time that another member reported seeing a mysterious device named “dining room sensor” on his device list even though he doesn’t have a dining room.
No way to know. We couldn’t force the failures to happen, but we couldn’t stop them from happening either.
FWIW.