diff --git a/components/agents/AgentDetailReferenceStitchDialog.tsx b/components/agents/AgentDetailReferenceStitchDialog.tsx
index 15b4216ae..dba96df1e 100644
--- a/components/agents/AgentDetailReferenceStitchDialog.tsx
+++ b/components/agents/AgentDetailReferenceStitchDialog.tsx
@@ -583,6 +583,12 @@ export function AgentDetailReferenceStitchDialog({
   const handleLinePointerDown = useCallback(
     (index: number) => (event: ReactPointerEvent<HTMLDivElement>) => {
       event.preventDefault();
+      event.stopPropagation();
+      try {
+        event.currentTarget.setPointerCapture(event.pointerId);
+      } catch {
+        // Older browsers may not support pointer capture for this target.
+      }
       setDraggingLineIndex(index);
     },
     []
@@ -876,7 +882,7 @@ export function AgentDetailReferenceStitchDialog({
                               <div
                                 onPointerDown={handleLinePointerDown(index)}
                                 className={cn(
-                                  "pointer-events-auto absolute inset-x-0 z-10 flex -translate-y-1/2 cursor-row-resize items-center justify-center",
+                                  "pointer-events-auto absolute inset-x-0 z-10 flex h-10 -translate-y-1/2 cursor-row-resize touch-none select-none items-center justify-center",
                                   draggingLineIndex === index && "z-20"
                                 )}
                                 style={{ touchAction: "none" }}