My wifi turns off as soon as I step out of room with internet box! Why?

I have an iPhone 6 and recently after a wind storm my wifi has not been working properly. It would only connect when I went into the same room as the internet box. I thought it was just my house but It happens everywhere. I do not think it was the wind storm that caused this.

I have tried restarting and shutting down my phone, updating to the latest version, taking out the sim card. I even tried restarting the internet but that did nothing. Everyone else in my house and coworkers have wifi but me. but I still do not know what could cause this.

Any suggestions or help.