color (colour) conform - HDR to SDR

You should not have Color conform set to SDR unless you are editing knto an SDR project. It looks like you changed the library to HDR but kept the project at Rec 709, which is SDR.

Now the library is HDR, if you try to do Modify on the project, Color Space should no longer be greyed out. Change it from Rec 709 to the proper HDR setting.

If I understand correctly, you need to make your library and project HDR to get HDR results.

What is happening now is that your HDR material is being conformed to an SDR project.

You can select your library in the browser sidebar, open the inspector and click "Modify", then choose "Wide Gamut HDR". Or perhaps it is better to just make a new library, in case this change may affect other things in it that are not supposed to be HDR. I have tried this and it seems to no harm anything, though.

Then make a new project and make sure to choose the appropriate Color Space:

Can you upload a short clip to Dropbox or WeTransfer? The link won’t appear in the forum but it will in forum notifications.

There are a lot of problems with DJI footage in the current OS and FCP. Larger formats don’t work at all.

Select the library and look in the Inspector for library properties. Make sure it’s set to Wide Gamut.

Please post screenshots of your library properties and of the media specs from the inspector. What camera shot the video and did you import it?