Will be good to get to the bottom of it, if you are only Manual ISO (what I normally use) from all that I have seen there is no special HDR processing going on in Jpeg or DNG, the key seems to be that Auto ISO (well according to DJI) is the...
There has been a post over on the DJI Forum and the moderators have stated that auto iso mode kicks in enhanced HDR for photos and video. Not sure if this relates to what you are seeing. Moderators are checking if this applies to jpegs and raw...