here is my step by step solution- The problem you are experiencing may be due to the configuration of the input stream and its relationship to the run loop. When you schedule the input stream in a run loop Make sure that the mode you are using is correct and consistent with the current loop running mode. If the mode is incorrect or incorrectly set The stream may not receive events as expected.

Here are the steps to troubleshoot and possibly fix the problem.

Loop Run Mode: Verify the loop run mode you are using. (NSDefaultRunLoopMode) is the production mode when the stream is scheduled. You can check the current mode using [NSRunLoop currentRunLoop].currentMode.

Stream Agent: Make sure the Stream Agent is set up correctly before launching the stream. A delegate must be assigned to the input stream before opening [channel inputStream].

Thread management: Because you are using a custom delivery queue. Make sure the queue doesn't block the main thread or cause a deadlock. If the queue is not available Streaming events may not be processed.

Bug Fix: Added logging to the method. stream:handleEvent: to confirm if a call is in progress. If not, The problem is probably in the streaming settings.

Data Availability: Since you said hasBytesAvailable returns false Ensures that data is sent correctly from the peripheral and that the L2CAP channel works as expected.

Encryption: Have you noticed that enforcing encryption helps hasBytesAvailable It can return the expected data. This indicates that encryption may be required for the stream to function properly. So make sure your BLE connection is properly configured for encrypted communication.