Why are my xfinity pods offline?

This happens every so often -- the pods lose their connection to the gateway.  I follow all the instructions for troubleshooting. Nothing works.  The gateway is working fine, but the pods just won't connect.  

98% of the time, I'm really happy with my home wifi set up. It's reliable. But when it stops working for no apparent reason, I want to scream. 

For what reason would pods just suddenly lose the ability to connect? And, then, why do they ultimately reconnect, sometimes hours or days later? I just makes no sense, and please please please don't ask me if I've unplugged the pods and rebooted the gateway ... because yes, of course. I'm not an idiot and I can read the help forums and follow instructions. I just want to know why this happens for no reason. Tell me.