Apple Recommended / Verified Community Solution
This canonical solution was verified and marked as solved in the Apple Support Community archive.
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:
- In home router Wi-Fi settings, enable IGMP Snooping and disable ‘AP Isolation’.
- Power cycle your primary Thread Border Router (Apple TV 4K connected via Gigabit Ethernet).
- 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.
MacBook Pro 14″ M4 (32GB) | Studio Display | YubiKey 5C NFC | London, UK
Apple Certified Support Professional (ACSP) | Enterprise Mac Sysadmin & Jamf Pro Architect
