fix

packages/svelte/src/internal/client/reactivity/batch.js

@@ -538,7 +538,13 @@ export class Batch {
 				// A batch was unskipped in a later batch -> tell prior batches to unskip it, too
 				if (is_earlier) {
 					for (const unskipped of this.#unskipped_branches) {
-						batch.unskip_effect(unskipped, (e) => batch.#defer_effects([e]));
+						batch.unskip_effect(unskipped, (e) => {
+							if ((e.f & (BLOCK_EFFECT | ASYNC)) !== 0) {
+								batch.schedule(e);
+							} else {
+								batch.#defer_effects([e]);
+							}
+						});
 					}
 				}
 

packages/svelte/tests/runtime-runes/samples/async-if-block-unskip/_config.js

@@ -21,7 +21,7 @@ export default test({
 		assert.htmlEqual(
 			target.innerHTML,
 			`
-			search search search
+			search search search search
 			<button>load</button>
 			<button>resolve</button>
 		`

packages/svelte/tests/runtime-runes/samples/async-if-block-unskip/main.svelte

@@ -32,5 +32,9 @@
 	{query}
 {/if}
 
+{#if !promise.loading}
+	{await query}
+{/if}
+
 <button onclick={() => query = 'search'}>load</button>
 <button onclick={() => resolvers.shift()?.()}>resolve</button>