We have a Grundig Freesat box which is behaving strangely. If I do a first time installation it scans & shows 100% signal strength, then searches for all the channels available & lists them as normal. But once it has finished scanning the major channels 1 to 5 etc.are fine but some channels, more 4, more 4+1, Yesterday etc. show "no signal" or appear to have poor reception ( picture & sound freezing). Checked cables to unit & appear to be OK swopped lead at LNB to a spare way, but I would have thought initial 100% scan signal would mean it is OK. Suspect box is goosed but thought I would ask first before investing in another one. Thanks