AVCaptureDeviceInput drops frames after first second running AVCaptureSession, with nativescript - objective-c

Question

I'm trying to create a video recorder in a nativescript plugin on the ios side which means that I am using the native Objective C Classes inside of the plugin to have a shared interface in the nativescript app with the android implementation.
I have the camera view loaded and I am trying to get access to the video frames from the AVCaptureSession. I created an object that implements the protocol to get the frames and for the first second the function captureOutput which has a parameter DidOutputSampleBuffer outputs the frames. But from then on all the frames are dropped and I do not know why. I can view that they are dropped because the function in the protocol, captureOutput with parameter DidDropSampleBuffer runs for every frame.
I tried changing the order of intializion for the avcapturesession but that didn't change anything.
Below is the main function with the main code to create the capture session and capture object. While this is typescript nativescript allows you to call native Objective C functions and classes so the logic is the same in objective c. I also create a VideoDelegate object in nativescript which corresponds to a class in Objective C which allows me to implement the protocol to get the video frames from the capture device output.
this._captureSession = AVCaptureSession.new();
//Get the camera
this._captureSession.sessionPreset = AVCaptureSessionPreset640x480;
let inputDevice = null;
this._cameraDevice = AVCaptureDevice.defaultDeviceWithMediaType(AVMediaTypeVideo);
//Get the camera input
let error: NSError = null;
this._captureInput = AVCaptureDeviceInput.deviceInputWithDeviceError(this._cameraDevice);
if(this._captureSession.canAddInput(this._captureInput)){
this._captureSession.addInput(this._captureInput);
}
else{
console.log("couldn't add input");
}
let self = this;
const VideoDelegate = (NSObject as any).extend({
captureOutputDidOutputSampleBufferFromConnection(captureOutput: any,sampleBuffer: any, connection:any): void {
console.log("Captureing Frames");
if(self.startRecording){
self._mp4Writer.appendVideoSample(sampleBuffer);
console.log("Appending Video Samples");
}
},
captureOutputDidDropSampleBufferFromConnection(captureOutput: any,sampleBuffer: any, connection:any): void {
console.log("Dropping Frames");
},
videoCameraStarted(date){
// console.log("CAMERA STARTED");
}
}, {
protocols: [AVCaptureVideoDataOutputSampleBufferDelegate]
});
this._videoDelegate = VideoDelegate.new();
//setting up camera output for frames
this._captureOutput = AVCaptureVideoDataOutput.new();
this._captureQueue = dispatch_queue_create("capture Queue", null);
this._captureOutput.setSampleBufferDelegateQueue(this._videoDelegate,this._captureQueue);
this._captureOutput.alwaysDiscardsLateVideoFrames = false;
this._framePixelFormat = NSNumber.numberWithInt(kCVPixelFormatType_32BGRA);
this._captureOutput.videoSettings = NSDictionary.dictionaryWithObjectForKey(this._framePixelFormat,kCVPixelBufferPixelFormatTypeKey);
this._captureSession.addOutput(this._captureOutput);
this._captureSession.startRunning();