MutableStateFlow does not recomposes value

I have a method that updates local value if I got a spicific json:

override fun onGameStartOpenWord(startOpenWord: StartOpenWord) {
    var word = _state.value.gameState!!.words.find { startOpenWord.word.id == it.id } ?: return
    val tempCopy = word.copy()
    word = word.copy(
            animationStart = startOpenWord.word.times.first().toULong(),
            animationEnd = startOpenWord.word.times.last().toULong()
        )
    val words = _state.value.gameState!!.words.toMutableList()
    val index = words.indexOf(tempCopy)
    logger.debug("Animation should start at ${word.animationStart}, updating word ${tempCopy.id} with index $index")
    words[index] = word
    val gameState = _state.value.gameState?.copy(words = words)
    _state.update { it.copy(gameState = gameState) }
    logger.debug(_state.value.gameState!!.words[index].animationStart)
}

The State created like this:

private val _state = reset() //MutableStateFlow<GameData>
val state = _state.asStateFlow()

Using state like this:

val model = ViewModelsStore.mainFrameViewModel //compose-jb does not have method viewModel<>(), using object to store
val data by model.state.collectAsState()
val stateWord = data.gameState!!.words.find { it.id == word.id }!!

val animationStart = stateWord.animationStart
val animationEnd = stateWord.animationEnd

if (animationStart != null) {
    //do animation stuff
}

Everything else updates correctly (recomposition starts), but the method above does not. However _state does actually update, logs show that clearly.
Debbuger showed me that before update() method gameState != _state.value.gameState, but after update() it is.

But recomposition didn't happen and animation didn't start. What is the problem?

Be careful with listeners. It was my mistake and gameState was overwritten by listener. So recompose didn't happen, because value changed too fast.