There have been about six different threads in the forums over the last few weeks about similar problems. Definitely report it to support If you are affected . They may be able to see something from their side.
It might be related to the following
About two weeks ago, some of my devides started going “offline” in the app, and in the developer console I see the same thing. Some of them would ‘recover’ when the switch was toggled. Some could even be controlled while being “offline” via Alexa voice controls that still seemed to work, although the app had lost all control of them. Still, they come and go, and I still have about 10 devices OFFLINE for now QUITE some time.
Smartthings support says they have a bug, and can’t provide any guidance as to time for a fix. They say I should go and remove then add them again (Takes LONG TIME, I have 10 smart apps on each device that would need to be setup again). Support also says other people have reported the same thing…
So what gives? I can’t run around the house and spend 4 hours fixing thi…