Homekit - Almost all devices suddenly not responding

So, I've had HomeKit up and running with a wide selection of devices (Hue, Lutron, Leviton, laGrande, Hunter Douglas, etc.) and for the most part haven't had any problems for about 6 months. A devices will lose connectivity and go into the "No Response" mode occasionally but I just delete the device and re-add it and we're back. Last night, I turned off the lights in my kitchen via Siri on HomePod and it was fine. I moved into the living room about 10 seconds later and asked Siri to turn on the lights and the HomePod responded that there was a problem with my devices and I needed to check my devices on the App. I got the dreaded white screen saying "Loading Accessories and Screens."

No problem, I've had that happen before so I let it go through it's paces and when it asked me if I wanted to start over with a new Home, I shut down the app and did the whole sign-out of iCloud and reboot across all my iOS devices, including my AppleTV. Bring it back up, and I am where I am now - 29 of my 35 accessories are non-responsive. I did a complete sign out and reboot again just to make sure, same result.

So, here I am wondering if I have to spend the next few hours completely rebuilding my Home and setting back up all my scenes. Anyone have any ideas?

Yes, all Apple devices are up to current software revisions. Yes, all accessories are at current software revisions. Yes, I've tried the reboot and iCloud sign out trick. The only thing that's odd are a couple things with my AppleTV. For some reason I can't connect to the AppleTV for keyboard input from any iOS device. And yes, we're all signed into the same iCloud account. Also, for the first time ever in the Home App I saw the AppleTV status change to "Needs Repair." I tapped on it and it changed from that status to "No Response." After one of the iCloud logouts and logins, it now shows as a reachable devices in HomeKit. Because of HomeKit's dependence on AppleTV as a hub, something makes me think this is all related but I'm out of troubleshooting options.

So, any ideas? Am I screwed?

iOS Devices: AppleTV 4th gen, iPhone 11 Pro, iPad 7th Generation (all current sw rev)