If that is only occurring on a specific channel, then it seems like interference from the machine to the receiver, and that's most likely to be caused by a radiated frequency-specific radiation "spike" from the machine flexible supply cable from the wall socket.
Therefore, if the machine is at all recent (like the last 20+ years!) , then it is probably breaching the radiated interference limits mandated by EU/UK legislation - and thus you should complain to the seller &/or manufacturer that it is not "legal"
OTOH, if all else fails, and from "another direction", pretty much every piece of domestic electronic equipment is, nowadays, not "earthed" via the main plug - thus adding an actual physical cable from the receiver case (assuming it's metal!) to the Earth pin in the mains plug may help to reduce the problems.