Severe Network Lag After Updating to FWA510 V1.18(ACGD.5)C0 – Router Mode Unusable

vanprasth

Dear Zyxel Support Team,

I am using the Zyxel FWA510 as a wireless router. After updating the firmware to V1.18(ACGD.5)C0, I encountered severe network lag and significant performance degradation.

Issue Description:

• After upgrading to V1.18(ACGD.5)C0, the network became extremely unstable.
• Web browsing, video streaming, and even basic internet usage suffered from noticeable delays and frequent disconnections.
• The network lag was so severe that the device became almost unusable.
• Downgrading back to V1.15(ACGD.3)C0 immediately restored stable and smooth network performance.

Maintenance History:

• Previously, I encountered a similar issue with my original FWA510 device and sent it for warranty service.
• Zyxel replaced it with another unit running firmware V1.15(ACGD.3)C0.
• The replacement device worked perfectly under V1.15 without any issues.
• However, after manually upgrading the replacement unit to V1.18(ACGD.5)C0, the same network lag problem reappeared.

Analysis:Based on these experiences, I strongly suspect that the issue stems from the firmware version V1.18(ACGD.5)C0, rather than any hardware defect.
Consistent behavior across different devices after the update points toward a firmware regression.

Additional Information:

• The device is operating in router mode.
• No network configuration changes were made except for the firmware update.

Request:Since the newer firmware offers important security improvements and patches known vulnerabilities,
I hope to continue using an updated version without sacrificing network stability.
Therefore, I sincerely request the Zyxel engineering team to investigate this issue and consider fixing it in a future firmware release.

Thank you very much for your attention and support.

Best regards,

vanprasth