diff --git a/datamodels/2.x/itop-portal-base/portal/templates/bricks/browse/mode_mosaic.html.twig b/datamodels/2.x/itop-portal-base/portal/templates/bricks/browse/mode_mosaic.html.twig
index cca764f54..17bbb7c20 100644
--- a/datamodels/2.x/itop-portal-base/portal/templates/bricks/browse/mode_mosaic.html.twig
+++ b/datamodels/2.x/itop-portal-base/portal/templates/bricks/browse/mode_mosaic.html.twig
@@ -397,15 +397,16 @@
 				}
 			}
 		};
-		
+
+		// N°3995: Loader is shown immediately, otherwise when we have a huge amount of items, we can have a bottleneck on the buildMosaic() function, blocking the display of the loader
+		showMosaicLoader();
 		$(document).ready(function(){
 			// Auto collapse item actions popup
 			$('body').click(function(){
 				$('#brick_content_mosaic .item-action-wrapper.collapse.in').collapse('hide');
 			});
 			
-			// Build the tree (collapsed)
-			showMosaicLoader();
+			// Build the mosaic (collapsed)
 			buildMosaic(oRawDatas);
 			hideMosaicLoader();
 			registerFilterListeners();
diff --git a/datamodels/2.x/itop-portal-base/portal/templates/bricks/browse/mode_tree.html.twig b/datamodels/2.x/itop-portal-base/portal/templates/bricks/browse/mode_tree.html.twig
index 1ecd1b988..e850f80d2 100644
--- a/datamodels/2.x/itop-portal-base/portal/templates/bricks/browse/mode_tree.html.twig
+++ b/datamodels/2.x/itop-portal-base/portal/templates/bricks/browse/mode_tree.html.twig
@@ -321,6 +321,8 @@
 			}
 		};
 
+		// N°3995: Loader is shown immediately, otherwise when we have a huge amount of items, we can have a bottleneck on the buildTree() function, blocking the display of the loader
+		showTreeLoader();
 		$(document).ready(function(){
 			// Init expand/collapse all buttons
 			$('#btn-collapse-all').on('click', function (oEvent) {
@@ -405,7 +407,6 @@
 			});
 			
 			// Build the tree (collapsed)
-			showTreeLoader();
 			buildTree(oRawDatas);
 			hideTreeLoader();
 			registerFilterListeners();