Then it’s probably just DNR, which would have been introduced in 2004. It would be worth checking the new Disney versions from 2019 to see if it’s in there (it shouldn’t be if it’s DNR, or should present itself differently since it’s a new scan). I’d do it but I no longer have Disney+ and I don’t have those Blu Rays.
Since no one spoke up I ended up grabbing a 2019 copy to check, and the blurring around the cape and trooper helmet distortion are still there. Maybe the “scan” they went back to was something that Lucas had altered at some point along the way, not sure. I guess it’s possible the 4k is better, I only checked the normal Blu Ray, but I doubt it.