You're absolutely right about this being a community forum - but by means of explanation, it's quite common on here for old threads (quite often solved) to be added-to by new users rather than starting their own post with their own issues.
I've re-read the post you originally replied to, also mentioned box restarts (always try that once), checking for the cables being finger-tight, and swapping HDMI cables. Nothing wrong with any of that.
The other thing you can check, which was alluded to in the post you replied to, was which channels are affected. Digital TV platforms (VM no exception) broadcast channels in "clusters" which often bear little resemblance to their EPG positions. A signal fault that affects one channel on a cluster (mux) will usually affect all channels - and cause, what seems to most people, random channels to pixellate.
The other poster mentioned BBC1-HD, is this one of your affected channels?
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