Not sure why you paid so much money for that item? there are a variety of those type of converters usually
available in the UK for under £10 so you could try your luck with another
However 'Blackmagic' makes professional equipment..
and these do not come along very often.
Ebay listing
https://tinyurl.com/kstrf6vr
On these Blackmagic units you have a 'component' input/output but you just use the green channel for composite out.