I am experiencing similar problems with my HDR Fox T2. I have power saving in standby set to off,as advised, to pass the signal when in stand-by.
If I connect my aerial cable directly to my Panasonic TX50cx802 the signal on all channels is fine.
If I then connect the T2 and have it powered up but the TV set to view it’s own channels the signal on all channels is fine.
If I now set the T2 to standby and continue to watch TV after about 15 Minutes some channels, on channel 56, start to show pixilation and bad signal warnings. If I then power up the T2 then all is fine again.
I am guessing that something is happening to the loop through circuit. This has only started happening recently. Does anyone have any ideas on this?