Inconsistency in using Capture code provided in SDK

Hi,

I have a 'DeckLink 4K Extreme 6G SDI' device, and for this I am using 'BlackMagic_DeckLink_SDK_10.9.5' on my Ubuntu 16.04 machine.

My application requires capturing of 500 video frames from external source through DeckLink card using Capture example provided in DeckLink_SDK. Here the video source is transmitting at 720p59.94 .
The connection done is, HDMI-OUT of the video source is connected to HDMI-IN of the DeckLink card.
The command I am using to run the capture executable once I start transmitting the video from external source is:
./Capture -d 0 -m 14 -p 2 -n 500 -v video.raw


So according to this DeckLink card should capture 500 frames and should stop capturing further frames.
But what I see is the DeckLink card goes on capturing the frames and doesn't stop once it captures 500 frames.

Unable to get what the problem is, waiting for any help. TIA

Regards

Maybe a moderator can move this topic to Software Development sub forum. As that is were all the developers are.