Look here https://www.youtube.com/watch?v=HRI2NiaX3_8&t=3363s 53min.
Here is original raw file vs dng file from DxO PL (or PureRAW).
Problem is with sharpness.
CaptureOne treats dng file as normal raw file and aplies all pre-settings, initial sharpening too.
Sharp dng file + initial sharpening gives big oversharpness.
Pay attention to this phenomenon and do something (any tutorial, comment)
Whatever corrections that are being done by PureRAW (sharpening, lens distortion correction, noise reduction, etc.) should be turned off in the next tool in your workflow. I’m not familiar with CaptureOne, but if it’s like most other tools, you might be able to create a profile or preset that has these things turned off.