Kotlin: ArrayList verification

Question

I am new to developping in kotlin and for my class, I have a tic tac toe game to create. I initialy create a MutableListOf at the top of my page that contain all the "box" of my playing grid.

private var playingBoard:MutableList<ImageView> = ArrayList()

then i had all the boxes of the grid to the list using a function like so :

private fun activerGrilleDeJeu() {
    playingBoard.add(view.a1)
    playingBoard.add(view.a2)
    playingBoard.add(view.a3)
    playingBoard.add(view.b1)
    playingBoard.add(view.b2)
    playingBoard.add(view.b3)
    playingBoard.add(view.c1)
    playingBoard.add(view.c2)
    playingBoard.add(view.c3)
}

I then have a function that check for a victory when i click on an image view on the board but my problem is that function never seem's to trigger :

private fun victoryListener(): Boolean{
    //Horizontal victory
    if(playingBoard[0] == playingBoard[1] && playingBoard[0] == playingBoard[2] && playingBoard[1] == playingBoard[2]){
        return true
    }

this is how i call that function

grilleDeJeu[0].setOnClickListener {
        ajouterjeton(grilleDeJeu[0])
        if(victoryListener()){
            if(tourPresent == joueur1){
                joueur1.score += 1
                tourPresent = joueur1
                resultat("Victoire de ${joueur1.prenom}")
            }
            else{
                joueur2.score += 1
                tourPresent = joueur2
                resultat("Victoire de ${joueur2.prenom}")
            }
        }

I had the same function for every "box" of the grid so I didn't had all of them but if you guy's need the full code just ask and i'll post it.