Google Nexus 5 :: Phone Wifi Only Connects When Screen Is On

I have this problem for some time now (at least since the marshmallow update). If I move my Nexus 5 to a different place, far from the current Wi-Fi AP, it does not connect to the nearest saved AP, it only does that if I wake up the screen.

The Wi-Fi works properly when the screen is off, I still get the notifications and all, I just have to stay connected to the same AP. I have tried everything to find what is the problem, but I can't find it.

I did a factory reset, it was working again, but when I did the first time Google account login, it started again, even on safe mode.

I thought I corrected it by doing another reset and not recovering my account , but when installing some apps it started again.

Every time I think I found the app that causes the problem and uninstall it, the Wi-Fi problem eventually returns
and I don't know what to do more.

What I have found out is that even uninstalling the app I think is the culprit, the Wi-Fi only works again properly if I reboot the phone, so maybe I have not found the app, and the Wi-Fi only works properly because I rebooted the phone?

The apps I have on my phone are the same I have in my Nexus 7 (2013), and with all those apps, the Wi-Fi works properly on the Nexus 7.

Is there anyway to know if is the phones fault, or some app (that makes the Wi-Fi not work properly on the Nexus 5,but not in the Nexus 7)?