This is such a convoluted subject for Witnesses in the U.S. Public schools K-12 start the day by standing and reciting the Pledge of Allegiance. Most professional sports leagues start their games with the national anthem.
As a Witness we were taught - for the Pledge of Allegiance it is alright to stand out of respect, but for the national anthem one must remain seated. The simple act of standing for the national anthem is an act of worship.
This made no sense to me. Like others, when I attended sporting events I would just head to the concession stands during the national anthem. As a kid I went with my friends and their father to a professional soccer (football) match. We sat during the national anthem. My friends' father was reading the newspaper while it played. We were heckled the whole time.