Little reactive problem with published collection

Hello,

I have this publish:

Meteor.publishComposite('game', function (tableId) {
    new SimpleSchema({
        tableId: { type: String },
    }).validate({ tableId });
    const userId = this.userId;
    return {
        find() {
            const indexes = {
                $and: [
                    { _id: tableId },
                    {
                        $or: [
                            { userId },
                            { users: { $in: [userId] } },
                        ],
                    },
                ],
            };
            const fields = {
                createdAt: 0,
            };
            return Tables.find(indexes, { fields });
        },
        children: [
            {
                find(table) {
                    return Scenes.find({ _id: table.sceneId, tableId: table._id });
                },
            },
            {
                find(table) {
                    if (table.userId !== userId) {
                        return this.ready();
                    }
                    const fields = {
                        name: 1,
                        tableId: 1,
                    };
                    return Scenes.find({ tableId: table._id }, { fields });
                },
            },
        ],
    };
});

Basically what it does is find a single table where this.userId is the creator or an user in the whitelist, then from there, it finds the current scene of the table and sends all the fields, on top of that, finds all the other scenes of the table but sends only the name of it (for a dropdown input so the user can select a scene).

Everything seems to be working fine (i have not yet tested deeply), i receive exactly the data i was looking for, until i change the current scene of the table ; i indeed receive the full data for this new current scene, but the data in minimongo from the older one do not get removed, i still have all the fields.

In this particular case, it is not so bad, but since i am learning Meteor and Mongo and everything really, and planning ahead of what i was going to do later, i would like to understand why it is behaving like that, what in my code should be changed to get what i want : only the full fields for the current scene, and all other scenes stripped of them except the name.

Thanks in advance.