Chromecast kills wifi router

[Kecia]

My Chromecast has this bug, where it randomly creates its own network or Wi-Fi signal. It labels its wifi as “Kecia.b”, which is just the name of the chromecast, with an added dot and a b.. Whenever it does this, it interferes with my Wi-Fi router to an extent where the wifi connection doesn’t work, and rebooting the router doesn’t help either. Unplugging the chromacast also does nothing. I can’t change the wifi to the chromecast either, which I’m assuming is because it’s “creating” its own. 
how do I fix this? My chromecast won’t work, stop sending out a wifi signal or let me change the wifi. The biggest issue lies with the fact that my wifi router won’t work until the chromecast stops sending the fake wifi signal, no matter if you turn it off and on. Even unplugging the chromecast from any source of power, which should stop the fake WiFi signal I suppose, still won’t help. My wifi router only starts working, when the chromecast stops what ever it is doing. 

also, it happened a few times before, but it’s been a while since last time, and I can’t seem to remember how to fix it. So as of right now, with the chromecast unplugged for 20-30+ minutes, Wi-Fi router restarted 5+ times, I still don’t have wifi, and I can’t cast anything:( 

[Byteguy]

It's actually the other way around.

Your router dies and then the Chromecast can't connect to the network so your Chromecast makes its own WiFi asking for help.

I've had issues with my router recently.  Every time the router goes off-line, all of my smart devices start making mini-WiFis like this because they want to know if they should connect somewhere else.   Once the network actually comes back up, all those devices see it, connect to it, and turn off their SOS signals.

You probably need to do what I had to do; contact your internet provider and tell them you are having network problem.   Mine replaced my modem and WiFi router and the problems went away.