If you're connecting to a Wi-Fi device, your iPad or iPhone may inform you that you may not be connected to the internet. This behavior can occur if you connect to a device like Sentry or Stratus. ADS-B Wi-Fi devices are not connected to the internet, and as a result, a pop-up is expected.
To resolve this issue, select Keep Trying Wi-Fi and limit your searches to data that is available via ADS-B. If you need to access the internet, you'll need to disconnect from your ADS-B device.
iOS Internet Connectivity Notification