nav2_bringup not generates costmap

edit

I do not have an answer for why launching all required nodes from one launch file works, but I wanted to share this snippet for any other people stumbling upon this issue.

I was following the First-Time Robot Setup Guide and also did not receive any costmaps in RViz.

I cloned the navigation2_tutorials which contains the sam_bot_description package. I then edited the display.launch.py file and added the following lines to the launch.Launchdescription([]) array near the bottom of the screen (with the corresponding imports, of course)

TimerAction(
        period=3.0,  # This should be large enough that Gazebo is loaded before SLAM is started
        actions=[
            IncludeLaunchDescription(
                PythonLaunchDescriptionSource(
                    os.path.join(get_package_share_directory('slam_toolbox'),
                                 "launch",
                                 "online_async_launch.py")
                )
            ),
        ]
    ),
    TimerAction(
        period=6.0,  # This sould be large enough that SLAM is fully started before the rest of nav2 is launched
        actions=[
            IncludeLaunchDescription(
                PythonLaunchDescriptionSource(
                    os.path.join(get_package_share_directory('nav2_bringup'),
                                 "launch",
                                 "navigation_launch.py")
                )
            ),
        ]
    ),

After launching this new file, I can see the costmaps in RViz.

Hopefully this helps other people to quickly get this example up and running.

Someone posted saying:

and I solved this problem by delete param "use_sim_time:=True".