I found out that my cable TV company, Comcast, uses a technology called HRC to improve video quality. My 5000X had a great live image but poor recorded image quality using the “cable” tuner setting. Once I switched the tuner setting in the setup menu to HRC and fine tuned to +9 everything worked fine.
Beware of this. It took some frustrating testing and luck to find it out.
Nothing in the user guide about it and little on the forums.