HTC M9. Why are my wifi connections disappearing?

[AC Question]

It's now becoming a daily thing. I wake up and my phone is connected to data when it should be on Wi-Fi. I check the Wi-Fi connections, but there are none available. I restart my phone and VOILA it's connected again and shows all the different signals. I do not understand what is going on here.

 

[B. Diddy]

Welcome to Android Central! Go to Settings>Wi-fi​, tap Menu>Advanced, and make sure it's not set to turn off wi-fi while asleep. Also, are there any power-saving modes turned on?