Gorm トランザクション エラー error = トランザクションがコミットまたはロールバックされました

func (d *DistributeService) Distribute(vehicleNumberPlate string, request model.DistributeRequest) (*model.DistributeResponse, error) {
    var response model.DistributeResponse
    response.Vehicle = vehicleNumberPlate
    var routeList []model.RouteResponse
    tx := d.repo.BeginTransaction()
    for _, routes := range request.RouteRequest {
        var routeResponse model.RouteResponse
        strategy, isStrategyExists := d.strategies[routes.DeliveryPoint]
        if isStrategyExists {
            resp, err := strategy.Distribute(routes.Deliveries, vehicleNumberPlate, tx)
            if err != nil {
                tx.Rollback()
                logrus.Errorf("Error while distributing: %v", err)
                return nil, err
            }
            routeResponse.DeliveryPoint = routes.DeliveryPoint
            routeResponse.Deliveries = *resp
            routeList = append(routeList, routeResponse)
        } else {
            logrus.Errorf("Invalid delivery point: %v", routes.DeliveryPoint)
            return nil, errors.New("invalid delivery point")
        }
    }
    response.RouteResponse = routeList
    err := d.checkSackPackagesAreUnloaded()
    tx.Commit()
    if err != nil {
        return nil, err
    }
    return &response, nil
}