So 1 hour to go until the World Cup game starts and the broadcaster station suddenly won't work. It had worked fine for a week or so after I swapped it for another old cable but now just a pixlated mess again. Fiddled around without luck for 20mins and then just gave up and went to look for a stream online. I unplugged the HDMI cable from the Laptop so I could put it on my lap and BAM the station just corrects itself back to a good reception. Plugged it back in again and the station is messed up. So I look round for some info and find a common cause for bad reception is old unshielded antenna cables. So I spent 20 bucks and bought a 5m long "rg6" cable and it works with the HDMI plugged in.
TL;DR: Check how old and cheap your cable is if you have reception trouble.
PS: If you buy these cables from an electronics store you might pay a small fortune. However you can get just the cables from specialist trade stores like Jaycar and make your own. Bunnings sell the completd antenna cables cheap too.