ZHA Regularly "Losing Connection to Radio"

Over the last 2 weeks-or-so, I am having to restart HA every 2-4 days to get ZHA going again. The logfile reports the following:

21T09:44:50.389735+08:00>>

2024-12-21 09:44:50.427 DEBUG (MainThread) [zigpy.application] Connection to the radio has been lost: <NcpFailure(code=<NcpResetCode.ERROR_EXCEEDED_MAXIMUM_ACK_TIMEOUT_COUNT: 81>)>

2024-12-21 09:44:50.437 DEBUG (MainThread) [homeassistant.components.zha.helpers] Connection to the radio was lost: ConnectionLostEvent(event_type=‘zha_gateway_message’, event=‘connection_lost’, exception=<NcpFailure(code=<NcpResetCode.ERROR_EXCEEDED_MAXIMUM_ACK_TIMEOUT_COUNT: 81>)>)

2024-12-21 09:44:50.450 DEBUG (bellows.thread_0) [zigpy.serial] Waiting for serial port to close

I presume this error means HA can’t talk to the coordinator (and hence downstream matters of my zigbee network are irrelevant to the problem)

My setup is:

  • Pi4B running HA (which is running very recent HAOS, Core etc - but not the absolute latest)
  • SkyConnect coordinator on a 3m USB3 extension cable connected to a USB 2 port on the Pi4B. The coordinator is 1.5m from any electronics.