Disable Internet access detection of WiFi networks?
If your device is rooted,  and have a firewall installed, you need to grant network access to Setup Wizard app (ID  # 1000), so it can resolve the Google look up. I verified this in my situation by turning off and on my firewall, and checking the firewall logs. 

I did not mess up with any editing of the captive portal settings. If you have the same problem, you have to forget the Wi-Fi networks in order for the SSID to be cleared. Once you grant network access to the Setup Wizard app in your firewall, the admiration point will disappear.