Check if you have configured the necessary background modes in your iOS project's Info.plist file. For beacon detection, you typically need to enable Uses Bluetooth LE accessories and Background fetch capabilities.

<key>UIBackgroundModes</key>
<array>
    <string>fetch</string>
    <string>bluetooth-central</string>
</array>

Also, make sure to request and handle background location permissions (Always authorization) in your Flutter app. This allows your app to access location updates, which are necessary for beacon detection in the background.

if still not working then check if the flutter_beacon plugin supports background beacon detection. Some plugins may have limitations or specific configurations required for background operation. Refer to the plugin documentation or GitHub repository for any specific instructions or updates related to background beacon detection.

Since flutter_beacon uses native APIs (CoreLocation on iOS), ensure that your native iOS code (Objective-C/Swift) includes the necessary configurations for background beacon monitoring:

Implementing background beacon detection typically involves setting up CLLocationManager in your iOS native code and configuring it for background monitoring.