Deep copy CVPixelBuffer for depth data in Swift

Question

I'm getting a stream of depth data from AVCaptureSynchronizedDataCollection and trying to do some processing on the depthDataMap asynchronously. I tried to deep copy the CVPixelBuffer since I don't want to block the camera while processing, but it doesn't seem the copied buffer is correct because I keep getting bad access errors. Here is the code I'm using to deep copy the CVPixelBuffer:

func duplicatePixelBuffer(input: CVPixelBuffer) -> CVPixelBuffer {
    var copyOut: CVPixelBuffer?
    let bufferWidth = CVPixelBufferGetWidth(input)
    let bufferHeight = CVPixelBufferGetHeight(input)
    let bytesPerRow = CVPixelBufferGetBytesPerRow(input)
    let bufferFormat = CVPixelBufferGetPixelFormatType(input)
        
    _ = CVPixelBufferCreate(kCFAllocatorDefault, bufferWidth, bufferHeight, bufferFormat, CVBufferGetAttachments(input, CVAttachmentMode.shouldPropagate), &copyOut)
    let output = copyOut!
    // Lock the depth map base address before accessing it
    CVPixelBufferLockBaseAddress(input, CVPixelBufferLockFlags.readOnly)
    CVPixelBufferLockBaseAddress(output, CVPixelBufferLockFlags.readOnly)
    let baseAddress = CVPixelBufferGetBaseAddress(input)
    let baseAddressCopy = CVPixelBufferGetBaseAddress(output)
    memcpy(baseAddressCopy, baseAddress, bufferHeight * bytesPerRow)
        
    // Unlock the base address when finished accessing the buffer
    CVPixelBufferUnlockBaseAddress(input, CVPixelBufferLockFlags.readOnly)
    CVPixelBufferUnlockBaseAddress(output, CVPixelBufferLockFlags.readOnly)
    NSLog("Pixel buffer original: \(input)")
    NSLog("Pixel buffer copy: \(output)")
    return output
}

I checked the two CVPixelBuffer objects before the return and it seems like there is no iosurface for the copied buffer. Also, there is a MetadataDictionary object in propagatedAttachments in the original, but in the copy the MetadataDictionary object is directly in attributes.

I've tried some of the other solutions on Stack Overflow with no luck since my planes are non-planar. Would appreciate any insights on this or if I should try a different approach entirely. Thanks!