Hi Shilpi,
Not sure why you are seeing this, I can simultaneously run CapturePreview and SignalGenerator from SDK 11.2 (running Desktop Video 12.1) with same DeckLink SDI 4K target.
The following is capture of DeviceStatusCSharp sample with active input and output. This sample was added in 11.6, you can run StatusMonitor example if running earlier version of Desktop Video. Can you check to see if you see similar?
- DeckLinkSDI4K_Capture-Playback.png (20.22 KiB) Viewed 1679 times
Regards
Cameron