I was unable to reproduce the issue that you are experiencing. That being said, here are some of the possible reasons for this behavior:
- The plugin is not included correctly to your app. If this is the case, please verify that you followed these steps to include the BLE plugin to your app.
- You are testing the plugin in the AppBuilder Simulator. Have in mind that most of the verified plugins cannot be tested in the simulator. List of plugins supported by the simulator you could find here.
- You are testing the plugin in the Telerik Platform Companion app. Have in mind that few of the verified plugins cannot be tested in the simulator. List of plugins supported by the Companion app you could find here.
- A BLE method is called before the Cordova onDeviceReady event. You could access your plugin only after this event has fired.
When you are testing plugins I would suggest deploying your app on an actual device.
I hope this helps. Please let me know if you require any further assistance.