I have recently installed Android 6 on my Nexus.
I also have AFWall+ for [un]blocking selected application from accessing internet.
However, every time I connect to a wifi an exclamation mark will appear and Android will soon disconnect from it. Also a popup message asks me to disconnect because it cannot connect to internet.
However I can access internet indeed via wifi.
What process should I add to whitelist in order for Android not to disconnectme after a few minutes?