Capture One refuses to write metadata to DNG files, even though that is the standard. They include it in a sidecar. And in the past we have seen they do other strange things with how they write the jpg preview to DNG files if at all. I wonder if you could use Adobe DNG converter on a Capture One DNG to "repair" it into a more standard DNG. I have not tried that, but if you post a link to one of your Capture One DNGs I could try.