Can we get more details? How are you testing? It sounds like you are expecting to get greater than 1 Gbps on a device downstream via the eero pro router. Step 1 is to plug a PC into the Modem via ethernet, reboot the device, and then check the speed from your ISP to the Arris. It may be you are only getting 960 Mbps, depending on the ISP and the configuration. Additionally, you’ll have to know what kind of Network Interface Card (NIC) is on the PC. It may not support anything over 1 Gbps. These steps will help determine whether there is a real problem or not.