Thanks for posting this clip:
https://www.youtube.com/watch?app=desktop&v=R18h5NmmhQc&ra=m
I agree with you, it’s good sportsmanship that fans on each side of the border can pitch in to sing the other anthem when the mic fails.
A better solution would be laws in both countries PROHIBITING the singing of either national anthem at any sporting event. I don’t like this ritual and I don’t think it improves anyone’s patriotism. But I realize that’s just me and the tradition will go on.