Hi everyone,

Short summary: This morning at around 05:05, my Sunrise Internet Box Fiber (Zyxel AX7501-B1) unexpectedly returned to factory settings. All my custom Wi-Fi/network settings disappeared, and Sunrise support could not explain why it happened or investigate it further.

What happened:

At around 05:00 I noticed that my normal 2.4 GHz / 5 GHz Wi-Fi networks had disappeared.
Instead, the original factory Sunrise Wi-Fi network was visible again.
My usual router admin password no longer worked.
I tried the factory admin credentials from the router label, and they worked.
After login, the router asked me to create a new admin password.
All my previous configuration was gone.
At around 08:10 the router showed an uptime of approximately 3 hours 5 minutes, which means it restarted at roughly 05:05.
The router logs are empty, so I cannot see what actually triggered the reset.

I called Sunrise support and explained that this was not simply a Wi-Fi outage or reboot, the router had apparently lost its complete configuration and returned to factory defaults.

The only possible explanation I was given was that there may have been a power interruption, and I was told to simply configure everything again. They could not provide any logs or further investigation. No help at all.

What concerns me is that a normal power interruption may explain a reboot, but it should not normally erase all persistent router configuration.

I have many devices, wired network settings and Home Assistant/smart-home equipment, so restoring everything takes significant time and more importantly, I still do not know why this happened or whether it can happen again.

Has anyone else experienced a Sunrise Internet Box suddenly factory-resetting itself?

Did you ever find out whether it was caused by:

a firmware update,
Sunrise remote provisioning,
a router fault,
power loss,
or something else?

I would also be interested to know whether Sunrise moderators can check any backend/provisioning logs around 05:05, since there is nothing useful left in the router’s local logs. And technical call with support did not help at all.