The Russian junior team was seated at the back of the plane, smoking cigarettes, not wearing any masks, and not listening to the flight attendants who were probably begging them to stop.
According to another source, it was not the players who broke the regulations aboard the plane, but rather the Russian junior team officials. Regardless of who was really responsible, these accounts appear to reinforce the idea that drinking, smoking, and refusal to wear a face mask appear to be the source of the problem.