Yep I had this same problem. Super weird. Shooting in 'none' is just fine.
What I did find is that I believe it has something to do with the dlog and cinelike sharpness values. If you go through each custom sharpness value 0 and above, they are all identical.... Except +3, which looks like 0 used to be. So it is functional if you must shoot in dlog, you just need to crank the sharpness all the way
Just got an inspire 1 pro two days ago. Already noticed this issue (muddy 4k footage in Dlog), even after updating to the latest firmware. DJI acknowledged this bug back in January, but apparently it still is not fixed?