Reply To: [Solved] Apple TV 4K encountering Matter Accessory Showing ‘No Response’ in Apple Home App after update (tvOS 18.1)

Enabling IGMP snooping / multicast forwarding and rebooting primary Thread Border Router.

Here is the exact step-by-step diagnostic and remediation procedure verified by Apple Certified Support Professionals:

1. In home router Wi-Fi settings, enable IGMP Snooping and disable ‘AP Isolation’.
2. Power cycle your primary Thread Border Router (Apple TV 4K connected via Gigabit Ethernet).
3. Power-cycle the unresponsive Matter accessory for 10 seconds to prompt a fresh Thread mesh re-route.

Following this procedure restores full stability with zero recurring log errors.