Mirror Data Table is NOT added SyncMarker automatically when creating

const FReferenceSkeleton& RefSkeleton = Skeleton->GetReferenceSkeleton();

// 3->4
TSet<FName> NamesByCategory[4]; 
ForeachRow<FMirrorTableRow>(TEXT("UMirrorDataTable::FindReplaceMirroredNames"), [&NamesByCategory] (const FName& Key, const FMirrorTableRow& Value) mutable
   {
      NamesByCategory[Value.MirrorEntryType].Add(Value.Name);
   }
);

auto AddMirrorRow = [this, &bChangedTable, &NamesByCategory](const FName& Name, const FName& MirroredName, EMirrorRowType::Type RowType)
{
   // directly add rows to avoid using FDataTableEditorUtils, which is not appropriate at this point
   // equivalent to FDataTableEditorUtils::AddRow(DataTable, BoneName);

   // add TEXT(":SyncMarker")
   static const FString CategoryName[] = { TEXT(":Bone"), TEXT(":Notify"), TEXT(":Curve"), TEXT(":SyncMarker") };
   if (!NamesByCategory[RowType].Contains(Name))

for (const FName& Notify : Skeleton->AnimationNotifies)
{
   FName MirroredName = FindReplace(Notify);
   if (!MirroredName.IsNone() && Skeleton->AnimationNotifies.Contains(MirroredName))
   {
      AddMirrorRow(Notify, MirroredName, EMirrorRowType::AnimationNotify);
   }
}

// add
for (const FName& SyncMarker : Skeleton->GetExistingMarkerNames())
{
   FName MirroredName = FindReplace(SyncMarker);
   if (!MirroredName.IsNone() && Skeleton->GetExistingMarkerNames().Contains(MirroredName))
   {
      AddMirrorRow(SyncMarker, MirroredName, EMirrorRowType::SyncMarker);
   }
}

const FSmartNameMapping* CurveSmartNames = Skeleton->GetSmartNameContainer(USkeleton::AnimCurveMappingName);