I kept getting this message in the New V3 app, And nothing seemed to fix it. The device worked fine with its own app and with echo, but I couldn’t even get to it in the smartthings app although previously it worked fine.
I tried all the usual recommendations, down to deleting the device from the app, deleting it from its own app and restoring it there. Deleting the smart things app and reinstalling it. Nothing fixed the problem.
Finally after reading a couple of threads that had the same message but for a different reason, I think, I ended up just trying it on my iPhone, which I personally don’t normally use. And it worked just fine. And once it worked fine in the iPhone, it worked fine on the iPad.
So I’m just putting this year in case anybody else runs into the same issue.