Listener not emiting to my view after updating its MutableLiveData

Question

I'm implementing the Billing library into my app, I have encounter that for building the BillingClient I need to create an interface to listen for updates.

Problem is that this BillingClient needs to be a singleton, so I have added this inside my Singleton module in my app

@Module
@InstallIn(SingletonComponent::class)
class BillingModule {

    @Provides
    @Singleton
    fun provideBillingClient(@ApplicationContext context: Context, purchasesUpdatedListener: PurchasesUpdatedListener): BillingClient {
        return BillingClient.newBuilder(context)
            .setListener(purchasesUpdatedListener)
            .enablePendingPurchases()
            .build()
    }

    @Provides
    fun getPurchasesUpdatedListener(): PurchasesUpdatedListener = BillingUpdateListener()
}

Now, I have created this BillingUpdateListener class, this is because I need to propagate the results of this listener to my UI.

class BillingUpdateListener @Inject constructor(): PurchasesUpdatedListener {

    private val _purchaseUpdateLiveData = MutableLiveData<PurchaseUpdate>()
    val purchaseUpdateLiveData: LiveData<PurchaseUpdate> = _purchaseUpdateLiveData

    override fun onPurchasesUpdated(
        billingResult: BillingResult,
        purchases: MutableList<Purchase>?
    ) {
        _purchaseUpdateLiveData.value = PurchaseUpdate(billingResult, purchases)
    }
}

data class PurchaseUpdate(
    val billingResult: BillingResult,
    val purchases: List<Purchase>?
)

ViewModel

@HiltViewModel
class MainViewModel @Inject constructor(
    billingListener: BillingUpdateListener
) : ViewModel() {

    val purchaseUpdateLiveData: LiveData<PurchaseUpdate> = billingListener.purchaseUpdateLiveData
}

MainActivity

@AndroidEntryPoint
class MainActivity : ComponentActivity() {

    @Inject
    lateinit var billingClient: BillingClient

    private val viewModel: MainViewModel by viewModels()

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        // Set status bar transparent
        WindowCompat.setDecorFitsSystemWindows(window, true)

        // Setup Listener
        viewModel.purchaseUpdateLiveData.observe(this, { purchaseUpdate ->
            Log.d("PurchaseUpdate", "Result: ${purchaseUpdate.billingResult}")
            Log.d("PurchaseUpdate", "Purchases: ${purchaseUpdate.purchases}")
        })
   setContent { ... }

My problem is that the listener is successfully executing inside my BillingUpdateListener but unsuccessfully sent to my ViewModel -> UI

it always executes at this point

But never coming back to my viewmodel and UI to execute the logs.

I have tried StateFlow - SharedFlow and they also don't work, I'm assuming that maybe the problem relies on the injection or some problems with instances, but I find it hard to trace this issue without anything.

Any clue ?