The new Doctor Who blurays being released are using low quality AI upscaling which is ruining the picture quality. There is already an ongoing petition for BBC to stop using these upscaling methods so that details in the frames do not get lost:
https://c.org/8kb4dbbPQx
If you are a fan of doctor who or just generally care about quality of physical media then please boost or otherwise repost this so that more people can see it.