UltraStudio 4K Mini scaling in 4k constellation

I’m playing a 4K video from a MacBook via thunderbolt into a UltraStudio 4K Mini. The video is playing perfectly on the built in screen. This is connected by SDI to a 4K Constellation but the image isn’t coming through in the correct scale. I am only getting about 25% of the image. It has cropped the rest. I can’t find a setting to adjust this, what am I missing. No scaling is required. The video I’m playing is 3840x2160 at 25p. That’s what all my equipment is set to so no scaling should be required. Anyone else experienced this? Any guidance appreciated.

Problem solved. I reinstalled the drivers and check the security options that I might have missed the first time, also had a play with the option of single of dual sdi outputs and all is now working properly.