21:42:42.321: Loaded scenes:
21:42:42.321: - scene 'Scene':
21:42:42.321: - source: 'Video Capture Device' (dshow_input)
21:42:42.321: - source: 'Video Capture Device 2' (dshow_input)
21:42:42.321: - source: 'Video Capture Device 3' (dshow_input)
It looks like you've added it 3 times. That won't work, they will interfere with each other and none of them will work.
It also looks like you may have chosen it as a device in Settings > Audio. You don't need to do that, webcams and capture cards can be added into a scene as a video capture source and you can also capture audio from them if they support it.
I tried difference setting to solve problem. But I'm still facing USB capture doesn't show as below log.
14:49:56.591: - scene 'RoM iPad Mini':
14:49:56.591: - source: 'Audio Input Capture' (wasapi_input_capture)
14:49:56.591: ------------------------------------------------
14:50:00.891: User switched to scene 'RoM iPad Mini'
14:50:05.583: User Removed source 'Audio Input Capture' (wasapi_input_capture) from scene 'RoM iPad Mini'
14:50:14.537: User added source 'Video Capture Device' (dshow_input) to scene 'RoM iPad Mini'
14:50:14.566: Video Capture Device: DecodeDeviceId failed
14:50:14.566: Video Capture Device: Video configuration failed
14:50:14.629: Video Capture Device: DecodeDeviceId failed
14:50:14.629: Video Capture Device: Video configuration failed
14:50:20.295: Video Capture Device: DecodeDeviceId failed
14:50:20.295: Video Capture Device: Video configuration failed