I recently got new 4k hardware installed by a Directv tech. When tuning in to 4k channels 104 or 106 the picture gets extremely dark after a minute or two. The tech stated that this is a known issue and there is no fix at this time. The stations are basically unwatchable. I tried a search in this forum to see if others are having this same issue but did not come up with anything. Are others experiencing this problem? Any input would be greatly appreciated.