MLS Season Pass

I am part of a family share plan. My son is the organizer. One of the members of our family share plan is a season pass holder to an mls team and he received an offer to get mls season pass. I’m putting the offer he received with this post. Subscription sharing is turned on. The member that received this offer is convinced that he has to sign in as the organizer (my son) in order for this to work even though he accepted the offer and shared it with the rest of us. I now see the mls season pass channel on my Apple TV app, but he says that in order for him to watch it he has to sign into my son’s Apple ID because my son is the organizer. I don’t think that is correct, but I’m not positive. I’ve told him several times that he should be able to see the channel since he accepted the offer under his account and should have access to the games, but he keeps telling me that he has to be signed in as the organizer in order to watch.