If you built a custom device picker in your app, this is a known issue that can happen when upgrading to v4.5.0 of the Cast SDK. In version 4.4.8 of the Cast SDK and earlier, device scanning was automatic. Beginning in version 4.5.0, you will need to explicitly call the startDiscovery method on the GCKDiscoveryManager class to initiate device discovery.

The reason for this change is because the Local Network Access (LNA) permissions prompt will appear after the app has scanned for the first time. This could result in permissions dialogs appearing at unexpected places in your app.

Developers who build a custom device picker for their app will be expected to provide an one-time interstitial prior to initiating device scanning for the first time in iOS 14.