I'm using RUT955 and Telenor SE. Normally the router provides a stable Internet connection, but when I connect my Chromecast the connection becomes unstable and often lose the Internet connection for a minute or so. When "down" I can still access the router admin pages that tells it is till connected. But if I try to surf, or use any apps on the phone, the Internet connection is gone, and the Wifi settings on the phone says "Connected, without Internet". The Chromecast also says I should connect to another wifi. If I just wait for about a minute, it will work again....
What should I do to fix this?