Timed Out Error when initializing Costmap2DROS

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I have multiple turtlebots on Gazebo simulator and try to get the positions of the obstacles.

tf::TransformListener listener(ros::Duration(10))
costmap_2d::Costmap2DROS costmap_ros_("my_costmap", listener);
costmap_2d::Costmap2D* costmap = costmap_ros_.getCostmap();

This initialization works when I do it with a single turtlebot by using turtlebot_world & amcl provided by the turtlebot_gazebo package. However, when I try it on the multiple turtlebots I launch, it doesn't work. The error I get is:

"Timed out waiting for transform from base_link to map to become available before running costmap, tf error: . canTransform returned after 0.1 timeout was 0.1."

Here are the params:

global_costmap_params.yaml

global_costmap:
  global_frame: map
  robot_base_frame: base_link
  update_frequency: 5.0
  static_map: true

local_costmap_params.yaml

local_costmap:
   global_frame: odom
   robot_base_frame: base_link
   publish_frequency: 2.0
   static_map: false
   rolling_window: true
   width: 6.0
   height: 6.0
   resolution: 0.05

Could it be because my frames are not like /map /base_link, but with the prefixes for each robot like /robot1_tf/map and /robot1_tf/base_link since I have multiple robots?

Any help will be appreciated.

My tf tree: http://docdro.id/YugFJ9C