Correct pose topic could not be subscribed via rviz

edit

I have defined a pose topic as below:

    pose_pub = n.advertise<geometry_msgs::Pose>("new_pose", 50);

But then, after assigning all related fields for position and orientation and also publishing it, I cannot opt for the topic of "/new_pose" under pose message. Instead, it offers me a topic which I never define it (goal(geometry_msgs/PoseStamped)). There is also a warning there saying that "no messages received". However, if I issue "rostopic echo -c /new_pose", there are changing values of position and orientation.

What is the possible culprit for this? I'm on ROS Electric anyway..