fix

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

@@ -179,7 +179,7 @@ export function boundary(node, props, children) {
 			var sources = boundary.fn.sources;
 			for (var [source, entry] of sources) {
 				if (source.v !== entry.v) {
-					mark_reactions(source, DIRTY);
+					mark_reactions(source, DIRTY, source);
 				}
 			}
 			sources.clear();

packages/svelte/src/internal/client/runtime.js

@@ -789,14 +789,11 @@ function flush_deferred() {
  * @returns {void}
  */
 export function schedule_effect(signal, source) {
-	if (scheduler_mode === FLUSH_MICROTASK) {
-		if (!is_micro_task_queued) {
-			is_micro_task_queued = true;
-			queueMicrotask(flush_deferred);
-		}
-	}
-
 	if (source && (signal.f & ASYNC_DERIVED) !== 0) {
+		if (active_effect === signal) {
+			set_signal_status(signal, MAYBE_DIRTY);
+			return;
+		}
 		var boundary = get_boundary(signal);
 		// @ts-ignore
 		var sources = boundary.fn.sources;
@@ -807,6 +804,13 @@ export function schedule_effect(signal, source) {
 		}
 	}
 
+	if (scheduler_mode === FLUSH_MICROTASK) {
+		if (!is_micro_task_queued) {
+			is_micro_task_queued = true;
+			queueMicrotask(flush_deferred);
+		}
+	}
+
 	last_scheduled_effect = signal;
 
 	var effect = signal;