diff --git a/backend/app/Services/Domain/Event/DuplicateEventService.php b/backend/app/Services/Domain/Event/DuplicateEventService.php
index d845cd7d81..3de5e46eff 100644
--- a/backend/app/Services/Domain/Event/DuplicateEventService.php
+++ b/backend/app/Services/Domain/Event/DuplicateEventService.php
@@ -127,7 +127,6 @@ public function duplicateEvent(
                     event: $event,
                     newEventId: $newEvent->getId(),
                     duplicateQuestions: $duplicateQuestions,
-                    duplicatePromoCodes: $duplicatePromoCodes,
                     duplicateCapacityAssignments: $duplicateCapacityAssignments,
                     duplicateCheckInLists: $duplicateCheckInLists,
                     oldToNewOccurrenceMap: $oldToNewOccurrenceMap,
@@ -136,6 +135,10 @@ public function duplicateEvent(
                 $this->createProductCategoryService->createDefaultProductCategory($newEvent);
             }
 
+            if ($duplicatePromoCodes) {
+                $this->clonePromoCodes($event, $newEvent->getId(), $oldProductToNewProductMap);
+            }
+
             if ($duplicateOccurrences && $duplicateProducts && ! empty($oldToNewOccurrenceMap)) {
                 $this->cloneOccurrenceProductSettings($oldToNewOccurrenceMap, $oldProductToNewProductMap, $oldPriceToNewPriceMap);
             }
@@ -240,7 +243,6 @@ private function cloneExistingProducts(
         EventDomainObject $event,
         int $newEventId,
         bool $duplicateQuestions,
-        bool $duplicatePromoCodes,
         bool $duplicateCapacityAssignments,
         bool $duplicateCheckInLists,
         array $oldToNewOccurrenceMap = [],
@@ -285,10 +287,6 @@ private function cloneExistingProducts(
             $this->clonePerProductQuestions($event, $newEventId, $oldProductToNewProductMap);
         }
 
-        if ($duplicatePromoCodes) {
-            $this->clonePromoCodes($event, $newEventId, $oldProductToNewProductMap);
-        }
-
         if ($duplicateCapacityAssignments) {
             $this->cloneCapacityAssignments($event, $newEventId, $oldProductToNewProductMap);
         }
@@ -377,14 +375,19 @@ private function clonePerOrderQuestions(EventDomainObject $event, int $newEventI
     private function clonePromoCodes(EventDomainObject $event, int $newEventId, array $oldProductToNewProductMap): void
     {
         foreach ($event->getPromoCodes() as $promoCode) {
+            $mappedProductIds = array_values(array_filter(
+                array_map(
+                    static fn ($productId) => $oldProductToNewProductMap[$productId] ?? null,
+                    $promoCode->getApplicableProductIds() ?? [],
+                ),
+                static fn ($productId) => $productId !== null,
+            ));
+
             $this->createPromoCodeService->createPromoCode(
                 (new PromoCodeDomainObject)
                     ->setCode($promoCode->getCode())
                     ->setEventId($newEventId)
-                    ->setApplicableProductIds(array_map(
-                        static fn ($productId) => $oldProductToNewProductMap[$productId],
-                        $promoCode->getApplicableProductIds() ?? [],
-                    ))
+                    ->setApplicableProductIds($mappedProductIds)
                     ->setDiscountType($promoCode->getDiscountType())
                     ->setDiscount($promoCode->getDiscount())
                     ->setExpiryDate($promoCode->getExpiryDate())
diff --git a/frontend/src/components/modals/DuplicateEventModal/index.tsx b/frontend/src/components/modals/DuplicateEventModal/index.tsx
index ee6d79ae29..80e4332471 100644
--- a/frontend/src/components/modals/DuplicateEventModal/index.tsx
+++ b/frontend/src/components/modals/DuplicateEventModal/index.tsx
@@ -76,12 +76,10 @@ export const DuplicateEventModal = ({onClose, eventId}: DuplicateEventModalProps
 
     useEffect(() => {
         if (eventQuery?.data) {
-            form.setValues({
-                title: eventQuery.data.title,
-                description: eventQuery.data.description,
-                start_date: utcToTz(eventQuery.data.start_date, eventQuery.data.timezone),
-                end_date: utcToTz(eventQuery.data.end_date, eventQuery.data.timezone),
-            });
+            form.setFieldValue('title', eventQuery.data.title);
+            form.setFieldValue('description', eventQuery.data.description);
+            form.setFieldValue('start_date', utcToTz(eventQuery.data.start_date, eventQuery.data.timezone));
+            form.setFieldValue('end_date', utcToTz(eventQuery.data.end_date, eventQuery.data.timezone));
         }
     }, [eventQuery.isFetched]);