fixes #78167

src/vs/base/browser/ui/grid/gridview.ts

@@ -348,6 +348,7 @@ class BranchNode implements ISplitView, IDisposable {
 		}
 
 		this.splitview.setViewVisible(index, visible);
+		this._onDidChange.fire(undefined);
 	}
 
 	getChildCachedVisibleSize(index: number): number | undefined {

src/vs/base/browser/ui/splitview/splitview.css

@@ -39,6 +39,7 @@
 	white-space: initial;
 	flex: none;
 	position: relative;
+	overflow: hidden;
 }
 
 .monaco-split-view2 > .split-view-container > .split-view-view:not(.visible) {
@@ -72,4 +73,4 @@
 .monaco-split-view2.separator-border.vertical > .split-view-container > .split-view-view:not(:first-child)::before {
 	height: 1px;
 	width: 100%;
-}
\ No newline at end of file
+}

src/vs/base/browser/ui/splitview/splitview.ts

@@ -125,7 +125,10 @@ abstract class ViewItem {
 		dom.addClass(container, 'visible');
 	}
 
-	abstract layout(): void;
+	layout(): void {
+		this.container.scrollTop = 0;
+		this.container.scrollLeft = 0;
+	}
 
 	layoutView(orientation: Orientation): void {
 		this.view.layout(this.size, orientation);
@@ -140,6 +143,7 @@ abstract class ViewItem {
 class VerticalViewItem extends ViewItem {
 
 	layout(): void {
+		super.layout();
 		this.container.style.height = `${this.size}px`;
 		this.layoutView(Orientation.VERTICAL);
 	}
@@ -148,6 +152,7 @@ class VerticalViewItem extends ViewItem {
 class HorizontalViewItem extends ViewItem {
 
 	layout(): void {
+		super.layout();
 		this.container.style.width = `${this.size}px`;
 		this.layoutView(Orientation.HORIZONTAL);
 	}