The device boots into failsafe mode successfully (LED flashing red at the expected rate), but I cannot get a network connection on any LAN/WAN port. The host machine reports "cable unplugged" - there is no link at all, not just an address issue.
What I've tried:
Triggered failsafe using the GPIO button method described in the wiki
Set a static IP on the host (192.168.1.10, gateway 192.168.1.1) since DHCP is disabled in failsafe
Tried all four LAN ports and the WAN port - same result on each
Verified the cable works fine with the device in normal operation
The device is otherwise fully functional: Wi-Fi, LAN switching, and LuCI all work normally. The problem is specific to failsafe mode.
I've reproduced this on two separate HH5A units, so it doesn't appear to be a hardware fault with a single device.
Is there a known issue with the HH5A switch not initialising in failsafe mode under 25.12? Is there a particular port that should be used, or anything else needed to bring up a link? Any pointers appreciated.
Bit more follow-up. I've confirmed that firmware 24.10.5 does have working failsafe mode (LAN1).
Firmware 25.12.0 rc1 does not - LAN ports 1 and 2 show no link in failsafe mode.
LAN ports 3 and 4 and WAN do show link but no response to ping or ssh from those ports
I note the GH bug you mentioned was closed a couple of days ago and the fix didn't work for you - as you have access to diagnostics (and I don't), could I trouble you to raise another bug report for the BT Home Hub 5A, please? Thank you