After the FWA505 was reset, it connected once, then disconnected and has remained offline

Zyxel_JoyLee

In some cases, mobile routers may appear offline in the Nebula Control Center (NCC) despite being physically online. Here are a few potential reasons and solutions:

Potential Causes

• Your Internet Service Provider (ISP) could be blocking the necessary TCP/UDP ports required for communication with the Nebula platform. Specifically, check if TCP ports 4335 and 6667 are being blocked.
• There may be an intermittent connectivity issue that causes the device to fail to report its status to the NCC.

Contact your ISP to ensure that the required ports (TCP 4335 and TCP 6667) are open. You can refer to the detailed guide :

https://community.zyxel.com/en/discussion/20616/mobile-router-understanding-about-nebula-cloud-control-status

.

https://community.zyxel.com/en/discussion/26630/how-to-troubleshoot-a-mobile-router-not-connecting-to-nebula

Moreover, disconnected issue is highly likely due to APN settings reverting to default/auto or Nebula cloud synchronization issues(if the device was previously registered on the Nebula Control Center).

To troubleshoot and get your FWA505 back online, please follow these steps:

1. Check Cellular status

a. LED Status: What color/behavior are you seeing on the Internet (globe icon) and Cellular Signal (SIM icon) LEDs? (e.g., is the cellular LED flashing blue, or is the internet LED solid red?)

b. SIM Card Status: Is the SIM card recognized when you log into the Web GUI, or does it show as locked/undetected?

2. Verify and Manually Configure APN Settings (Most Common Cause)

After a factory reset, the router defaults to "Auto" APN selection. Many carriers require manual configuration to maintain a stable connection.

a. Connect a computer or phone directly to the FWA505’s Wi-Fi network or LAN port.

b. Open a web browser and navigate to the local management page (default IP is typically 192.168.1.1).

c. Log in using the admin credentials printed on the device label.

d. Go to Network Setting > Broadband > Cellular APN.

e. Disable Auto and manually input the APN, username, and password provided by your cellular carrier. Save the changes.