Yes it did have to do with the plane. They didn't know what would happen with radio interference at the time. Heck even the 777-200 was grounded because of on the ground signals not even in the aircraft

https://liveandletsfly.com/boeing-faa-777-787-5g/

LAX, Jeju Korea grounded the 777-200. Recently after putting a fence under the flight path to stop instagram-ers at Jeju airport, they then re-allowed the 777-200 to fly here again