Hi @Rainmans and welcome to our forum!
Was the 11 Mbit/s measured through WiFi or a cabled connection? If it was through WiFi, could you do another speedtest on a device that's connected to your router directly with an internet cable? Make sure there's no devices connected in between. I'm curious what your speed is then.
If it's quicker then, please use our Wifi Manager to improve the internet speed. Achieving 1 Gbit/s through WiFi is unlikely, but some improvement from 11 Mbit/s should be possible.
If this was measured using a cabled connection, could you make sure the cable is directly connected and has no interference from other hardware? If that doesn't improve it, try a different cable. Hopefully we’ll see some results then!
In order to measure the speed of your Internet connection, never measure through wifi. Always use a computer which is connected to the network with a network cable.
If possible use the Ookla Speedtest app from the Microsoft Store on a Windows computer.
I improved the speed by disabling the 2.4 network. So now have only 5. Any advice what are the best settings to allow both networks to operate? I need 2.4 for some of my devices. Thank you!