I am writing to request technical support for a speed issue I am experiencing with my ER605 router.

My current setup includes three WAN connections:

- WAN 1: 1000 Mbps

- WAN 2: 300 Mbps

- WAN 3: 100 Mbps

WAN 1 and WAN 2 are configured as primary WANs, while WAN 3 is set as a backup.

The issue is specific to WAN 1. When I connect my ISP modem directly to my computer, I consistently receive speeds between 900 and 950 Mbps. However, when I connect the same modem to the WAN 1 port of the ER605 and connect my computer to the ER605 LAN port, the speed drops to 600–650 Mbps.

To isolate the problem, I disconnected all switches and other devices during testing, but the speed remained capped at 650 Mbps. Please note that WAN 2 and WAN 3 are delivering their expected speeds; the throughput issue is exclusive to WAN 1.

Could you please assist me in troubleshooting why the ER605 is not delivering the full throughput of my WAN 1 connection?