Joint Controller plugin not creating topic in ignition gazebo

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I've made a simple robot with 3 joints and I've applied the joint state publisher, pose publisher and joint controller plugins.

The joint state publisher and pose publisher plugins create their topics and I can interface them with ros_ign_bridge without issues. However, the joint controller plugin isn't creating a topic for the joint I specified.

Here is the SDF:

Here is the ignition GUI showing all topics:

As shown in the last figure, there is no joint control topic for the 'joint_shoulder2base' joint.

Can some one help me with this issue? Thanks :)