I'm having this same problem. There doesn't seem to be a software option to automatically connect to certain known wifi's.
I don't want it to auto log on to every known network the phone senses. I want to select which known networks to auto log on to.
For instance, I have both 2.4 and 5 wifi's in my house. Sometimes the 2.4 provides better connectivity but usually the 5 is best. Of course, they are both "known" networks. If the phone is constantly switching back and forth between them as I walk through the house it causes connection issues. So, I used to be able to set the 5 to automatically connect and not the 2.4. That way the phone automatically connects to the 5 and I can switch to the 2.4 if I need to. I can't find a way to do that with this Moto G 4th gen.
The other problem I'm having is that the Moto G doesn't seem to automatically log on to the known wifi's in the house. I have to go to the wifi setting and manually log on.
How do I control these settings.