Orbi RBR350 Satellite constant white flashing light

Last night I wanted to attached the my Orbi RBR350 to another router for testing purposes. I switched the device from router to AP mode. After the switch one of the 2 satellites wouldn't reconnect to the router, and now the light just flashes white.

Normally I have the networked connected to a Virgin Media router which is in modem mode. However, I've been testing a Tenda 4G+ router and wanted to bridge the network to that. I did this a few weeks ago without issue.

I've performed a factory reset on all 3 devices. Only the router and 1 satellite reconnect.

The non-working device will connect to the network via a LAN cable with the light turning to blue before going out. I can access the admin page, but the status wheel just keeps turning. I can also access the debug and hidden info menu, but not firmware update.

Also, I can connect to the device via my laptop and a static IP address via 192.168.1.250.

The device also seems to create 3 wifi connections : Backhaul, Guest and whc-D8A9A5.

I've tired a number of hard resets, and forcing a firmware update (might be doing this wrong though) but nothing seems to work. It also won't let me connect via telnet.

In the debug page there are a number of errors:

2.4G Coexist:            read failed for part : No error information in nvram_create_local opening file /tmp/nvram failed: No such file or directory Error opening file /tmp/nvram : No such file or directory in func nvram_create_hash Error while creating hash of nvram NVRAM Init error
2.4G Channel:            read failed for part : No error information in nvram_create_local opening file /tmp/nvram failed: No such file or directory Error opening file /tmp/nvram : No such file or directory in func nvram_create_hash Error while creating hash of nvram NVRAM Init error
5G Channel:              read failed for part : No error information in nvram_create_local opening file /tmp/nvram failed: No such file or directory Error opening file /tmp/nvram : No such file or directory in func nvram_create_hash Error while creating hash of nvram NVRAM Init error
start page:              read failed for part : No error information in nvram_create_local opening file /tmp/nvram failed: No such file or directory Error opening file /tmp/nvram : No such file or directory in func nvram_create_hash Error while creating hash of nvram NVRAM Init error

The kit is only 10 months old and has worked without issue until yesterday.

I was wondering if anyone else has had the same issue?

Thanks in advance.