fixes

packages/svelte/src/internal/client/dom/blocks/boundary.js

@@ -238,10 +238,17 @@ export function boundary(node, props, children) {
 
 			if (main_effect) {
 				destroy_effect(main_effect);
+				main_effect = null;
+			}
+
+			if (pending_effect) {
+				destroy_effect(pending_effect);
+				pending_effect = null;
 			}
 
 			if (failed_effect) {
 				destroy_effect(failed_effect);
+				failed_effect = null;
 			}
 
 			if (hydrating) {

packages/svelte/src/internal/client/dom/blocks/svelte-component.js

@@ -52,8 +52,9 @@ export function component(node, get_component, render_fn) {
 	block(() => {
 		if (component === (component = get_component())) return;
 
-		if (component) {
 		var defer = boundary !== null && should_defer_append();
+
+		if (component) {
 			var target = anchor;
 
 			if (defer) {
@@ -61,14 +62,14 @@ export function component(node, get_component, render_fn) {
 				offscreen_fragment.append((target = document.createComment('')));
 			}
 
-			pending_effect = branch(() => render_fn(anchor, component));
+			pending_effect = branch(() => render_fn(target, component));
+		}
 
 		if (defer) {
 			add_boundary_callback(boundary, commit);
 		} else {
 			commit();
 		}
-		}
 	}, EFFECT_TRANSPARENT);
 
 	if (hydrating) {