any suggestions, tried normal fixes
I don't know what you call "normal fixes". Channels found in that frequency area can be affected by location of cable-boxes to other devices, appliances, type of lighting used, fans, etc. It could be for either audio or video.
If you already checked cables for loose connections, or faulty cable ends, unstacked any components, and reset all boxes after checking the cables and found "no joy", I would check the lower SD channel for FOX. Is the same problem happening there too? Does the problem occur using Television speakers versus a separate speaker system?