This is Reddit, so I have to start with the usual caveats. Everyone's situation is different. What worked for me may not work for you. Nothing here is definitive. I don't think I have all the answers. I'm often wrong. Other than that, I had a fairly stable Thread network, but every now and then some devices wouldn't respond and wouldn't come back even after days of waiting. For context, I have about 22 contact sensors, 24 smart plugs, and a Schlage Encode Plus - all using Thread. For Thread Border routers, I have 6 HomePod minis and a 2nd generation Apple TV 4K wired (acting as the main hub). As you may know, Eve Energy is also a Thread Router (not to be confused with a Border Thread Router like a HomePod mini or Apple TV). After a lot of trial and error, I've come to the conclusion that sometimes Thread routers "hang" and stop routing correctly, but the endpoint device doesn't know there's a problem and doesn't choose another path. So Thread endpoint devices that are routed through the "blocked" Thread router go unanswered. Again, I have no "proof". Just a lot of trial and error. But after removing some of my Thread Smart Plugs/Thread Pipes and doing a bunch of testing, I found that stability improved dramatically. I did this based on a little guesswork combined with figuring out which part of my house those devices that wouldn't come back were located. The smart plugs removed were all Eve, with a mix of HomeKit over Thread and Matter over Thread. So there you go. Approaching a person to improve their Thread network. I hope some will find this useful.