diff --git a/src/Controller/Booking/Create/Step2Controller.php b/src/Controller/Booking/Create/Step2Controller.php
index 7b2f9df..af2deae 100644
--- a/src/Controller/Booking/Create/Step2Controller.php
+++ b/src/Controller/Booking/Create/Step2Controller.php
@@ -132,8 +132,9 @@ class Step2Controller extends AbstractController
             throw $this->createNotFoundException(sprintf('Participant at index %d does not exist', $index));
         }
 
-        // Enrich with fresh availability data
-        $this->travelDataService->enrichWithFreshAvailabilities($bookingDto->travel);
+        // Fetch fresh availabilities when entering participant form
+        // This ensures up-to-date data and populates cache for subsequent HTMX refreshes
+        $this->travelDataService->enrichWithFreshAvailabilities($bookingDto->travel, cached: false);
 
         // Create form with booking_context option
         $form = $this->createParticipantForm($bookingDto, $index);
diff --git a/src/Controller/Booking/Edit/IndexController.php b/src/Controller/Booking/Edit/IndexController.php
index ee58a41..0e31caf 100644
--- a/src/Controller/Booking/Edit/IndexController.php
+++ b/src/Controller/Booking/Edit/IndexController.php
@@ -169,6 +169,10 @@ class IndexController extends AbstractController
             return $this->redirectToRoute('app_booking_edit', ['id' => $id]);
         }
 
+        // Fetch fresh availabilities when entering participant form
+        // This ensures up-to-date data and populates cache for subsequent HTMX refreshes
+        $this->travelDataService->enrichWithFreshAvailabilities($bookingDto->travel, cached: false);
+
         // Create wrapper DTO for email uniqueness validation
         $wrapper = new ParticipantEditDto(
             participant: $participant,
diff --git a/src/Service/TravelDataService.php b/src/Service/TravelDataService.php
index 568a9e9..2996fa3 100644
--- a/src/Service/TravelDataService.php
+++ b/src/Service/TravelDataService.php
@@ -523,12 +523,12 @@ class TravelDataService
      * Gets availability data for a travel date.
      *
      * @param int  $dateId The travel date ID for API call
-     * @param bool $cached Whether to use cached data (default: false, TTL when cached: 60 seconds)
-     * @param int  $ttl    Cache TTL in seconds when $cached is true (default: 60 seconds)
+     * @param bool $cached Whether to use cached data (default: false, TTL when cached: 300 seconds)
+     * @param int  $ttl    Cache TTL in seconds when $cached is true (default: 300 seconds)
      *
      * @return ServiceAvailabilityResponse|null The availability data or null if not available or error occurred
      */
-    public function getAvailabilityData(int $dateId, bool $cached = false, int $ttl = 60): ?ServiceAvailabilityResponse
+    public function getAvailabilityData(int $dateId, bool $cached = false, int $ttl = 300): ?ServiceAvailabilityResponse
     {
         if ($cached) {
             $cacheKey = sprintf('availability_%d', $dateId);