diff --git a/mantidimaging/gui/test/gui_system_liveviewer_test.py b/mantidimaging/gui/test/gui_system_liveviewer_test.py
index a0e3564c0c6..8945bb2498f 100644
--- a/mantidimaging/gui/test/gui_system_liveviewer_test.py
+++ b/mantidimaging/gui/test/gui_system_liveviewer_test.py
@@ -37,6 +37,7 @@ def tearDown(self) -> None:
 
     def test_open_close_intensity_profile(self):
         self.assertEqual(self.live_viewer_window.splitter.sizes()[1], 0)
+        QTest.qWait(SHORT_DELAY * 4)
         self.live_viewer_window.intensity_action.trigger()
         QTest.qWait(SHORT_DELAY)
         QTest.qWait(SHOW_DELAY)
@@ -49,6 +50,7 @@ def test_open_close_intensity_profile(self):
         QTest.qWait(SHOW_DELAY)
 
     def test_roi_resized(self):
+        QTest.qWait(SHORT_DELAY * 4)
         self.live_viewer_window.intensity_action.trigger()
         QTest.qWait(SHORT_DELAY)
         wait_until(lambda: not np.isnan(self.live_viewer_window.presenter.model.mean).any(), max_retry=600)
diff --git a/mantidimaging/gui/windows/live_viewer/presenter.py b/mantidimaging/gui/windows/live_viewer/presenter.py
index 03cea3fe9a9..227bc5c5889 100644
--- a/mantidimaging/gui/windows/live_viewer/presenter.py
+++ b/mantidimaging/gui/windows/live_viewer/presenter.py
@@ -52,6 +52,7 @@ class LiveViewerWindowPresenter(BasePresenter):
     op_func: Callable
     thread: QThread
     worker: Worker
+    old_image_list_paths: list[Path] = []
 
     def __init__(self, view: LiveViewerWindowView, main_window: MainWindowView):
         super().__init__(view)
@@ -96,20 +97,25 @@ def update_image_list(self, images_list: list[Image_Data]) -> None:
             self.handle_deleted()
             self.view.set_load_as_dataset_enabled(False)
         else:
+            images_list_paths = [image.image_path for image in images_list]
             if not self.view.live_viewer.roi_object and self.view.intensity_action.isChecked():
                 self.view.live_viewer.add_roi()
             self.model.roi = self.view.live_viewer.get_roi()
             self.model.images = images_list
-            if images_list[-1].image_path not in self.model.mean_paths:
+            if (sorted(list(self.old_image_list_paths) + images_list_paths[-1:])) == images_list_paths:
                 try:
                     image_data = self.model.image_cache.load_image(images_list[-1])
                     self.model.add_mean(images_list[-1], image_data)
+                    self.update_intensity_with_mean()
                 except ImageLoadFailError as error:
                     logger.error(error.message)
-            self.update_intensity(self.model.mean)
+            else:
+                self.model.clear_mean_partial()
+                self.run_mean_chunk_calc()
             self.view.set_image_range((0, len(images_list) - 1))
             self.view.set_image_index(len(images_list) - 1)
             self.view.set_load_as_dataset_enabled(True)
+            self.old_image_list_paths = images_list_paths
 
     def select_image(self, index: int) -> None:
         if not self.model.images: