diff --git a/quickstep/src/com/android/launcher3/taskbar/KeyboardQuickSwitchController.java b/quickstep/src/com/android/launcher3/taskbar/KeyboardQuickSwitchController.java
index d4213e59dd..1595a0f3a5 100644
--- a/quickstep/src/com/android/launcher3/taskbar/KeyboardQuickSwitchController.java
+++ b/quickstep/src/com/android/launcher3/taskbar/KeyboardQuickSwitchController.java
@@ -169,7 +169,7 @@ public final class KeyboardQuickSwitchController implements
                             shouldShowDesktopTasks ? RecentsFilterState.EMPTY_FILTER
                                     : RecentsFilterState.getDesktopTaskFilter(),
                             (tasks) -> {
-                                processLoadedTasks(tasks, taskIdsToExclude);
+                                processLoadedTasks(wasOpenedFromTaskbar, tasks, taskIdsToExclude);
                                 mQuickSwitchViewController.updateQuickSwitchView(
                                         mTasks,
                                         wasOpenedFromTaskbar ? 0 : mNumHiddenTasks,
@@ -223,22 +223,24 @@ public final class KeyboardQuickSwitchController implements
         }
 
         mExcludedTaskIds = taskIdsToExclude;
-        mTaskListChangeId = mModel.getTasks(shouldShowDesktopTasks ? RecentsFilterState.EMPTY_FILTER
-                : RecentsFilterState.getDesktopTaskFilter(), (tasks) -> {
-            processLoadedTasks(tasks, taskIdsToExclude);
-            // Check if the first task is running after the recents model has updated so that we use
-            // the correct index.
-            mQuickSwitchViewController.openQuickSwitchView(
-                    mTasks,
-                    wasOpenedFromTaskbar ? 0 : mNumHiddenTasks,
-                    /* updateTasks= */ true,
-                    currentFocusedIndex == -1 && !mControllerCallbacks.isFirstTaskRunning()
-                            ? 0 : currentFocusedIndex,
-                    shouldShowDesktopTasks,
-                    mHasDesktopTask,
-                    mWasDesktopTaskFilteredOut,
-                    wasOpenedFromTaskbar);
-            });
+        mTaskListChangeId = mModel.getTasks(
+                shouldShowDesktopTasks ? RecentsFilterState.EMPTY_FILTER
+                        : RecentsFilterState.getDesktopTaskFilter(),
+                (tasks) -> {
+                    processLoadedTasks(wasOpenedFromTaskbar, tasks, taskIdsToExclude);
+                    // Check if the first task is running after the recents model has updated so
+                    // that we use the correct index.
+                    mQuickSwitchViewController.openQuickSwitchView(
+                            mTasks,
+                            wasOpenedFromTaskbar ? 0 : mNumHiddenTasks,
+                            /* updateTasks= */ true,
+                            currentFocusedIndex == -1 && !mControllerCallbacks.isFirstTaskRunning()
+                                    ? 0 : currentFocusedIndex,
+                            shouldShowDesktopTasks,
+                            mHasDesktopTask,
+                            mWasDesktopTaskFilteredOut,
+                            wasOpenedFromTaskbar);
+                });
     }
 
     private boolean shouldExcludeTask(GroupTask task, Set<Integer> taskIdsToExclude) {
@@ -246,11 +248,12 @@ public final class KeyboardQuickSwitchController implements
                 && task.getTasks().stream().anyMatch(t -> taskIdsToExclude.contains(t.key.id));
     }
 
-    private void processLoadedTasks(List<GroupTask> tasks, Set<Integer> taskIdsToExclude) {
+    private void processLoadedTasks(boolean openedFromTaskbar, List<GroupTask> tasks,
+            Set<Integer> taskIdsToExclude) {
         mHasDesktopTask = false;
         mWasDesktopTaskFilteredOut = false;
 
-        if (enableAltTabKqsFlatenning.isTrue()) {
+        if (enableAltTabKqsFlatenning.isTrue() && !openedFromTaskbar) {
             processLoadedTasksCombined(tasks, taskIdsToExclude);
         } else if (mControllers.taskbarDesktopModeController.shouldShowDesktopTasksInTaskbar()) {
             processLoadedTasksOnDesktop(tasks, taskIdsToExclude);
diff --git a/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/TaskbarOverflowTest.kt b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/TaskbarOverflowTest.kt
index a23ebe9914..7aa9640827 100644
--- a/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/TaskbarOverflowTest.kt
+++ b/quickstep/tests/multivalentTests/src/com/android/launcher3/taskbar/TaskbarOverflowTest.kt
@@ -17,6 +17,7 @@
 package com.android.launcher3.taskbar
 
 import android.animation.AnimatorTestRule
+import android.app.WindowConfiguration
 import android.content.ComponentName
 import android.content.Intent
 import android.os.Process
@@ -25,7 +26,6 @@ import android.platform.test.annotations.EnableFlags
 import android.platform.test.flag.junit.SetFlagsRule
 import androidx.test.core.app.ApplicationProvider
 import com.android.launcher3.BubbleTextView
-import com.android.launcher3.Flags.FLAG_ENABLE_ALT_TAB_KQS_FLATENNING
 import com.android.launcher3.Flags.FLAG_ENABLE_MULTI_INSTANCE_MENU_TASKBAR
 import com.android.launcher3.R
 import com.android.launcher3.dagger.LauncherAppSingleton
@@ -358,7 +358,6 @@ class TaskbarOverflowTest {
 
     @Test
     @TaskbarMode(PINNED)
-    @DisableFlags(FLAG_ENABLE_ALT_TAB_KQS_FLATENNING)
     fun testPressingOverflowButtonOpensKeyboardQuickSwitch() {
         val maxNumIconViews = maxNumberOfTaskbarIcons
         // Assume there are at least all apps and divider icon, as they would appear once running
@@ -418,7 +417,6 @@ class TaskbarOverflowTest {
 
     @Test
     @TaskbarMode(PINNED)
-    @DisableFlags(FLAG_ENABLE_ALT_TAB_KQS_FLATENNING)
     fun testHotseatItemTasksNotShownInKQS() {
         val maxNumIconViews = maxNumberOfTaskbarIcons
         // Assume there are at least all apps and divider icon, as they would appear once running
@@ -453,6 +451,43 @@ class TaskbarOverflowTest {
             .containsExactlyElementsIn(listOf(0) + (2..<createdTasks).toList())
     }
 
+    @Test
+    @TaskbarMode(PINNED)
+    fun testFullscreenTasksNotShownInKQS() {
+        val maxNumIconViews = maxNumberOfTaskbarIcons
+        // Assume there are at least all apps and divider icon, as they would appear once running
+        // apps are added, even if not present initially.
+        val initialIconCount = currentNumberOfTaskbarIcons.coerceAtLeast(2)
+        val hotseatItems = createHotseatItems(1)
+
+        val targetOverflowSize = 5
+        val createdTasks = maxNumIconViews - initialIconCount + targetOverflowSize
+        createFullscreenAndDesktopTasksFromPackages(
+            listOf("fakeFullscreen"),
+            listOf("fake") +
+                listOf(hotseatItems[0]?.targetPackage ?: "") +
+                List(createdTasks - 2) { "fake" },
+        )
+
+        runOnMainSync {
+            val taskbarView: TaskbarView =
+                taskbarUnitTestRule.activityContext.dragLayer.findViewById(R.id.taskbar_view)
+            taskbarView.updateItems(
+                recentAppsController.updateHotseatItemInfos(hotseatItems as Array<ItemInfo?>),
+                recentAppsController.shownTasks,
+            )
+        }
+
+        tapOverflowIcon()
+        // Keyboard quick switch view is shown only after list of recent task is asynchronously
+        // retrieved from the recents model.
+        runOnMainSync { recentsModel.resolvePendingTaskRequests() }
+
+        assertThat(getOnUiThread { keyboardQuickSwitchController.isShownFromTaskbar }).isTrue()
+        assertThat(getOnUiThread { keyboardQuickSwitchController.shownTaskIds() })
+            .containsExactlyElementsIn(listOf(1) + (3..<createdTasks + 1).toList())
+    }
+
     @Test
     @TaskbarMode(PINNED)
     @EnableFlags(FLAG_ENABLE_PINNING_APP_WITH_CONTEXT_MENU)
@@ -578,12 +613,36 @@ class TaskbarOverflowTest {
     }
 
     private fun createDesktopTaskWithTasksFromPackages(packages: List<String>) {
-        val tasks =
-            packages.mapIndexed({ index, p ->
+        createFullscreenAndDesktopTasksFromPackages(emptyList(), packages)
+    }
+
+    private fun createFullscreenAndDesktopTasksFromPackages(
+        fullscreenPackages: List<String>,
+        desktopPackages: List<String>,
+    ) {
+        val defaultDisplayId = context.virtualDisplay.display.displayId
+        val tasks: List<GroupTask> =
+            fullscreenPackages.mapIndexed({ index, p ->
+                SingleTask(
+                    Task(
+                        Task.TaskKey(
+                            index,
+                            WindowConfiguration.WINDOWING_MODE_FULLSCREEN,
+                            Intent().apply { `package` = p },
+                            ComponentName(p, ""),
+                            Process.myUserHandle().identifier,
+                            2000,
+                        )
+                    )
+                )
+            })
+
+        val desktopTasks =
+            desktopPackages.mapIndexed({ index, p ->
                 Task(
                     Task.TaskKey(
-                        index,
-                        0,
+                        index + fullscreenPackages.size,
+                        WindowConfiguration.WINDOWING_MODE_FREEFORM,
                         Intent().apply { `package` = p },
                         ComponentName(p, ""),
                         Process.myUserHandle().identifier,
@@ -592,10 +651,11 @@ class TaskbarOverflowTest {
                 )
             })
 
-        val displayId = context.virtualDisplay.display.displayId
-        recentsModel.updateRecentTasks(listOf(DesktopTask(deskId = 0, displayId, tasks)))
-        for (task in 1..tasks.size) {
-            desktopTaskListener?.onTasksVisibilityChanged(displayId, task)
+        recentsModel.updateRecentTasks(
+            tasks + listOf(DesktopTask(deskId = 0, defaultDisplayId, desktopTasks))
+        )
+        for (task in 1..desktopTasks.size) {
+            desktopTaskListener?.onTasksVisibilityChanged(defaultDisplayId, task)
         }
         runOnMainSync { recentsModel.resolvePendingTaskRequests() }
     }