I have just installed a RAW photo app on my iPhone.
It produces .dng files but, at the moment, although I can read it in Affinity Photo, Luminar and on1 Photo Raw and can even read it in Photoshop CS3 by converting it to another version of DNG, I still can't read it in DxO PhotoLab.
IS there anything I can do to the EXIF data to convince DxO to play nicely?
Do you have any dng file that works with DXO? Perhaps DXO simply doesn't support dng.
If you do have a working dng file, how was that created and what did you do differently for the non working files?
A quick google search I did early came up with a couple links that indicated DXO supported some, but not all DNG files.
It seems to me it's unlikely that it's a problem with the metadata, more that DXO has incomplete DNG support.