HA loses Mater thread connection (Apple HomePod mini) from time to time - IPV6 Network is "unreachable" from time to time

isaacc · April 20, 2026, 7:26pm

Hi Everyone.

I’m having an issue with Matter over Thread devices becoming unavailable in HA, while they continue to work fine in Apple Home. The whole thread network that’s shared credentials in Home Assistant kind of “drops out” from time to time, making devices unavailable.

Setup:

Mac mini M4 running HA through VMWare Fusion
Apple HomePod Mini
Devices are added straight to Home Assistant using the shared thread network (from the HomePod)

Problems:
Devices will initially work fine with Home Assistant, then they will randomly all become unavailable, where they still work through Apple Home.
Home assistant then goes the IPV6 route to the Thread network, where the logs of the Python matter server says:

2026-04-20 17:59:33.113 (MainThread) INFO [matter_server.server.device_controller] <Node:41> Re-Subscription succeeded
2026-04-20 18:02:07.654 (Dummy-2) CHIP_ERROR [chip.native.DMG] Subscription Liveness timeout with SubscriptionID = 0x5516b11c, Peer = 01:0000000000000004
2026-04-20 18:02:07.658 (MainThread) INFO [matter_server.server.device_controller] <Node:4> Subscription failed with CHIP Error 0x00000032: Timeout, resubscription attempt 0
2026-04-20 18:02:08.951 (MainThread) INFO [matter_server.server.device_controller] <Node:4> Re-Subscription succeeded
2026-04-20 18:02:13.394 (Dummy-2) CHIP_ERROR [chip.native.DMG] Subscription Liveness timeout with SubscriptionID = 0xf88fedf9, Peer = 01:0000000000000003
2026-04-20 18:02:13.398 (MainThread) INFO [matter_server.server.device_controller] <Node:3> Subscription failed with CHIP Error 0x00000032: Timeout, resubscription attempt 0
2026-04-20 18:02:14.687 (MainThread) INFO [matter_server.server.device_controller] <Node:3> Re-Subscription succeeded
2026-04-20 18:15:11.756 (Dummy-2) CHIP_ERROR [chip.native.DMG] Subscription Liveness timeout with SubscriptionID = 0x681fe0c9, Peer = 01:0000000000000029
2026-04-20 18:15:11.760 (MainThread) INFO [matter_server.server.device_controller] <Node:41> Subscription failed with CHIP Error 0x00000032: Timeout, resubscription attempt 0
2026-04-20 18:15:11.964 (Dummy-2) CHIP_ERROR [chip.native.IN] SendMessage() to UDP:[fde7:3e28:f487:0:bcfd:af77:42c7:7d0b]:5540 failed: src/inet/UDPEndPointImplSockets.cpp:417: OS Error 0x02000065: Network is unreachable
2026-04-20 18:15:11.965 (Dummy-2) CHIP_ERROR [chip.native.-] src/inet/UDPEndPointImplSockets.cpp:417: OS Error 0x02000065: Network is unreachable at src/app/OperationalSessionSetup.cpp:254
2026-04-20 18:15:11.965 (Dummy-2) CHIP_ERROR [chip.native.DMG] Failed to establish CASE for re-subscription with error 'src/inet/UDPEndPointImplSockets.cpp:417: OS Error 0x02000065: Network is unreachable'
2026-04-20 18:15:11.966 (MainThread) INFO [matter_server.server.device_controller] <Node:41> Subscription failed with OS Error 0x02000065: Network is unreachable, resubscription attempt 1
2026-04-20 18:15:17.186 (Dummy-2) CHIP_ERROR [chip.native.IN] SendMessage() to UDP:[fde7:3e28:f487:0:bcfd:af77:42c7:7d0b]:5540 failed: src/inet/UDPEndPointImplSockets.cpp:417: OS Error 0x02000065: Network is unreachable
2026-04-20 18:15:17.187 (Dummy-2) CHIP_ERROR [chip.native.-] src/inet/UDPEndPointImplSockets.cpp:417: OS Error 0x02000065: Network is unreachable at src/app/OperationalSessionSetup.cpp:254
2026-04-20 18:15:17.187 (Dummy-2) CHIP_ERROR [chip.native.DMG] Failed to establish CASE for re-subscription with error 'src/inet/UDPEndPointImplSockets.cpp:417: OS Error 0x02000065: Network is unreachable'
2026-04-20 18:15:17.188 (MainThread) INFO [matter_server.server.device_controller] <Node:41> Subscription failed with OS Error 0x02000065: Network is unreachable, resubscription attempt 2
2026-04-20 18:15:17.188 (MainThread) INFO [matter_server.server.device_controller] <Node:41> Marked node as unavailable
2026-04-20 18:15:23.598 (Dummy-2) CHIP_ERROR [chip.native.IN] SendMessage() to UDP:[fde7:3e28:f487:0:bcfd:af77:42c7:7d0b]:5540 failed: src/inet/UDPEndPointImplSockets.cpp:417: OS Error 0x02000065: Network is unreachable
2026-04-20 18:15:23.598 (Dummy-2) CHIP_ERROR [chip.native.-] src/inet/UDPEndPointImplSockets.cpp:417: OS Error 0x02000065: Network is unreachable at src/app/OperationalSessionSetup.cpp:254
2026-04-20 18:15:23.598 (Dummy-2) CHIP_ERROR [chip.native.DMG] Failed to establish CASE for re-subscription with error 'src/inet/UDPEndPointImplSockets.cpp:417: OS Error 0x02000065: Network is unreachable'
2026-04-20 18:15:23.599 (MainThread) INFO [matter_server.server.device_controller] <Node:41> Subscription failed with OS Error 0x02000065: Network is unreachable, resubscription attempt 3

If anyone has any insight on this this would be greatly appreciated, thank you!

DocMarc73 · April 21, 2026, 7:07am

Try following command in Terminal:
ha docker options --enable-ipv6=true

After that restart HA

wmaker · April 21, 2026, 6:46pm

Not sure, but there have been reports that Apple TBRs will from time to time change the Thread network including the address prefix that devices on the Thread network are to use and when this happens, then devices become unreachable. It seems the Apple TBR has some special sauce to handle it, but HA Matter Server has no idea this is going on until the devices later report their new addresses. Again, I don’t know that this is the problem.

However if restarting the Matter Server solves the problem rather quickly (say ~1 minute), then I would recommend switching to the new Matter Server “Beta” as it perhaps better at this.