Sorry. Dolby Vision. I equate the two in my head. But DV is what your issue actually is. (If you play the video on your PC say with MPC-HC you'll see that the videos all have a purple tint to them if your monitor doesn't support DV (which it most likely doesn't))
Plex seems to not particularly care anymore about managing to properly render DV videos on non DV equipment, and there's a long list of complaints on their forum regarding this, especially because about a year ago it did work.
Usually (I suppose), DV would be identified in the filename of whatever media you're pirating so it may be possible to tell Radarr to skip those releases and try another one, but the real issue here is Plex and you'd be best talking on the forum and join the chorus there regarding this.