Keasy: not seen any such issues like that ever, perhaps you got a faulty processor or another tv hardware fault especially if it occurs on all sources (virgin/sky, inbuilt apps, pc, console etc).
I watch MMA weekly for 8hrs+, so people get knocked out within a split second and would have noticed any stuttering or distracting issue. Since you tried it on and off that also may point to a faulty processing of the TV perhaps mainboard issue.
id still at least try record some videos, send it to LG support and see an engineers opinion or if they can book a TV repair see if it improves the motion, nothing else to lose really.
Sweet Caroline:
I am pretty harsh on LG and their QC process, but having said that Sony and other OLED panel manufacturers get their fair share of TV faults and issues, take the new grid effect issue it was recently confirmed even the new 2021 Sonys OLEDS get them these are 3K+ sets, and Sony do a lot more QC on their side then LG but even Value electronics store failed a few Sony sets since they did not meet their QC expectations quality wise, its still a panel lottery sadly with any brand
I have Freeview HD on mine mate.
It happens on DTV/Freeview and Virgin Media V6 stb