Moto G3 not connecting or detecting familiar wifi networks...

[AC Question]

My phone is not connecting to Wi-Fi networks it has in the past... It won't connect or detect or recognize Wi-Fi networks that it has used before, and where I know I have had an internet connection before. It just all of a sudden won't even pick up that those routers are putting out a signal. But other Wi-Fi networks that I have not connected to show up... I can still use the 4G, but I can't use those Wi-Fi networks.. Help..