Help please. SmartThings doesn't control things anymore

I’m at a total loss. Had about 19 devices composed of dimmers and switches working perfectly with Alexa, etc. I added a couple of Leviton dimmers and that was working for a couple hours.

The next morning, half of my devices were offline and the ones that were weren’t responding to commands.

I tried a variety of suggestions, including resetting the hub (red button), repairing the mesh network via the app, replacing devices, and removing devices.

Nothing seems to be working. What’s the next step here???

Hate to not be able to offer anything other than reach out to support, but I think that’s where you need to go now.