Blackmagic Design Intensity Shuttle USB 3

As you are telling it works on OBS, consider this checklist:

  1. Is Desktop Video software properly installed? Look for Desktop Video Setup and make sure the device is listed.
  2. Is the device already in use in OBS? Close all other programs and restart the machine if necessary.
  3. Does the channel video mode matches one supported by your device?
  4. Have you tried changing the keyer mode to default?

Those cards are very “special”, never seemed to work as advertised and gave me many headaches in the past.

Well I just noticed the log says:
Could not determine whether device supports requested video format: 720p50
Either the Desktop video software does not support the device properly or CasparCG doesn’t.