diff --git a/app/(chat)/api/chat/route.ts b/app/(chat)/api/chat/route.ts
index 573f170ee..924967975 100644
--- a/app/(chat)/api/chat/route.ts
+++ b/app/(chat)/api/chat/route.ts
@@ -7272,13 +7272,17 @@ export async function POST(request: Request) {
               productImageCount: sceneProductSlotCount,
               includeModelImage: sceneModelSlotEnabled,
             });
-            const rawSceneSlotPrompt =
-              sceneSlot?.promptTemplate || selectedAgentPreset.promptTemplate || "";
-            const dedupedSceneSlotPrompt = dedupeAgentSlotPromptAgainstWorkflow({
-              workflowPrompt: hiddenPromptText || null,
-              slotPrompt: rawSceneSlotPrompt,
-              modeType: "scene_generation",
-            });
+            const shouldAppendSceneSlotPrompt = !hiddenPromptText;
+            const rawSceneSlotPrompt = shouldAppendSceneSlotPrompt
+              ? sceneSlot?.promptTemplate || selectedAgentPreset.promptTemplate || ""
+              : "";
+            const dedupedSceneSlotPrompt = rawSceneSlotPrompt
+              ? dedupeAgentSlotPromptAgainstWorkflow({
+                  workflowPrompt: hiddenPromptText || null,
+                  slotPrompt: rawSceneSlotPrompt,
+                  modeType: "scene_generation",
+                })
+              : "";
             const scenePrompt =
               buildAgentSceneWorkflowPrompt({
                 workflowPrompt: hiddenPromptText || null,
@@ -7302,6 +7306,7 @@ export async function POST(request: Request) {
               includesWorkflowPrompt: Boolean(hiddenPromptText),
               includesUserSupplementPrompt: Boolean(sanitizedUserSupplementPrompt),
               includesModelImage: sceneModelSlotEnabled,
+              shouldAppendSceneSlotPrompt,
               includesSceneSlotPrompt: Boolean(dedupedSceneSlotPrompt),
               productImageCount: sceneProductSlotCount,
               uploadedImageCount: sharedUploadedImageUrls.length,
@@ -7345,9 +7350,13 @@ export async function POST(request: Request) {
                 resolvedImageCount,
                 sourceImageCount: sourceImageUrls.length,
                 sourceAssetCount: sourceAssetIds.length,
-                promptStrategy: hiddenPromptText || sanitizedUserSupplementPrompt
-                  ? "workflow_only"
-                  : "legacy_template_fallback",
+                promptStrategy: hiddenPromptText
+                  ? "workflow_plus_image_lock"
+                  : rawSceneSlotPrompt
+                    ? "legacy_template_fallback"
+                    : sanitizedUserSupplementPrompt
+                      ? "workflow_plus_user_supplement"
+                      : "workflow_only",
                 promptLength: String(scenePrompt || `生成${selectedAgentPreset.name}`).length,
                 aspectRatio:
                   typeof mergedImageParams.aspectRatio === "string"