By default, when you turn on “Connect to Wi-Fi networks automatically” in Settings, your Android device is connected to every Wi-Fi that it remembers. For example, every time you return home or reach the office, you will see that your Android device will automatically turn on Wi-Fi and connect to your home or office Wi-Fi. This is Android’s “Automatic Connection”.
Although this feature is useful in most situations, sometimes this feature is annoying. For example, you log in to McDonald’s and your Android automatically switches to McDonald’s Wi-Fi because you remember it. But, McDonald’s wants you to enter a captive portal that you don’t already have, and your existing downloads have stopped. Here’s an easy way to prevent it in the future.
Disable Auto-Connect on Certain Wi-Fi Networks
Open the Settings menu and you will have Wi-Fi connected at the top. Tap on it and under the Wi-Fi network page, tap the gear icon next to the connected Wi-Fi.
Under Wi-Fi settings, tap the “Advanced” option for further settings. When done, navigate down and you will have the option labeled “Automatically connect.” Tap to turn off Auto-connect for certain Wi-Fi.
After you have done this, your Android will not automatically connect to this special Wi-Fi network. Even though it will still be connected automatically to other WiFi networks whose settings you haven’t changed.
Now, this optional Auto-connect has been available on Android skins maybe since Android 9 or Android 10. Arrived at OneUI a while ago and I have this feature on Android 10 myself.
Google brings a number of privacy changes on Android 10. One that is under the radar is the Random Address MAC and many Wi-Fi changes.