I have 3 UIButton instances in a horizontal UIStackView. I get the focus on the first one. But when I swipe to the right, the next button does not get focus...

Hello. I have an interactive component based on UISegmentedControl that is displayed in the top header of a UICollectionView laid out using UICollectionViewCompositionalLayout. The UICollectionView is displayed within a container UIViewController. That container has call to action buttons. When the focus is on one of these buttons and the user swipes down on the remote, I would like the focus to be redirected to the top header. Where should I place the UIFocusGuide ? I have tried adding it to the container UIViewController at the same level as the buttons and UICollectionView (in between) to no avail.