VLAN list disappeared in Nebula after weekend, other settings unchanged

Hello,

After the weekend (20.10.2025), we noticed unusual behavior across all Zyxel switches connected to Nebula Cloud.

Symptoms:

• The entire VLAN list disappeared - only VLAN 1 remained visible in Nebula and on the devices.
• However, all other configurations, including port and trunk settings, remained unchanged.
• The PVID of all ports was reset to the default value (VLAN 1).
• The devices were not rebooted - uptime remained the same.
• The issue was first noticed at around 06:00 UTC on Monday.
• Before this incident, Nebula displayed available firmware updates, but after it happened, the update notifications disappeared.

Devices affected:

Zyxel XGS1935-52
Zyxel GS1920-24HP

Additional detail:

We recently added one more switch to the same network site, about two weeks ago.
On this newly added switch, the trunk configuration was also reset, unlike on the others.
So, the older switches lost only their VLAN table (while keeping other settings), but the new one lost both VLANs and trunk settings.

Another note:

Yesterday there was a major AWS incident.

I can’t confirm whether it’s related, but could this outage have affected Nebula Cloud services in any way?

Questions:

1. Are there any known cases where Nebula Control Center might reset VLAN tables without manual admin actions?
2. Could this be related to a cloud configuration sync, license level, or the process of adding a new device?
3. Is there any information suggesting the AWS outage could have impacted Nebula availability or configuration storage?