fixes #65491

src/vs/workbench/parts/debug/browser/baseDebugView.ts

@@ -190,6 +190,11 @@ export abstract class AbstractExpressionsRenderer
 			data.toDispose.push(dom.addDisposableListener(inputBox.inputElement, 'blur', () => {
 				wrapUp(true);
 			}));
+			data.toDispose.push(dom.addDisposableListener(inputBox.inputElement, 'click', e => {
+				// Do not expand / collapse selected elements
+				e.preventDefault();
+				e.stopPropagation();
+			}));
 		};
 
 		return data;

src/vs/workbench/parts/debug/electron-browser/watchExpressionsView.ts

@@ -118,7 +118,7 @@ export class WatchExpressionsView extends ViewletPanel {
 
 		const element = e.element;
 		// double click on primitive value: open input box to be able to select and copy value.
-		if (element instanceof Expression) {
+		if (element instanceof Expression && element !== this.debugService.getViewModel().getSelectedExpression()) {
 			this.debugService.getViewModel().setSelectedExpression(element);
 		} else if (!element) {
 			// Double click in watch panel triggers to add a new watch expression