Auxiliary device doesn't register with Central

Hello everybody, 

We have added another Firewall to the infrastructure of a client, forming a HA-Cluster of XGS-Firewalls.
The primary device is already registered with Central, but I can't register the Auxiliary no matter what I try.

When I try to add it via Central and type in the serial number (I tried it individually and with the SN of the primary device seperated by comma), the firewall GUI starts loading, gives me the green box on top saying "Firewall successfully registered with Central" but it actually does not.

I already tried multiple times and waited for some time, but the device neither shows up in Central, nor does it update it's unregistered status in the firewall itself
(image below).

Is this a bug? Should I deregister the primary device and try again? 

  

Thanks a lot! 



Edited TAGs
[edited by: Raphael Alganes at 1:50 PM (GMT -7) on 30 Jul 2025]