Chromecast causing wifi interference problem issues – resolved and fixed

The enemy in our home

My notebook sometimes would not connect to Wifi. So I used Wifi Analyzer on my phone to find out what's going on. There was another signal on our wifi channel. 
First, I guessed the neighbors had a too strong wifi signal. So we switched channels. But after a while, I realized, the other signal would follow our channel switches and interfere again. Within less than 30 seconds. Could it be, that this evil signal was something going wrong in our router? Nope. It turned out the Chromecast Video and Chromecast Audio (we have both) are broadcasting their own signal, although sometimes without SSID. After an update it seems to be "Chromecast Audio.a" and "Chromecast Video.b". And it turns out, this is the Guest Mode of Chromecast. So we disabled Chromecast guest mode by using the now renamed "Home" app (was called "Chromecast" before). And voila, wifi is back to normal.

(This blog post is a SEO experiment. The number one ranked post for the "query chromecast interfering with wifi" was from Edward Grigson and all credit for this fix goes to him. :)