dynamic tf broadcaster updates stale/intermittent in tf view_frames

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Hello everybody,

Description: Ubuntu 18.04.2 LTS, Jetson nano, Ros melodic

My robot platform is an inverted pendulum, and trying to implement a dynamic transform between the base_link (centered between wheels and fixed w/r/t gravity vector), and base_frame (co-located with base_link, but includes the pitch measurement). The sensor that is providing the attitude measurement also produces a visual odometry measurement, so I have an odom_listener node that will send an updated base_link to base_frame transform, and a base_link to camera_odom_frame transform on every new measurement.

However, when I run "tf view_frames", I will only infrequently see the base_link to base_frame or camera_odom_frame nodes, and if I do, the measurements are typically many seconds old. If I run "tf tf_echo base_link base_frame", I can usually see tf broadcast updates, but interestingly, they can show the same "At time" values for multiple broadcasts:

$ rosrun tf tf_echo base_link base_frame 

At time 1568583863.323
- Translation: [0.000, 0.000, 0.000]
- Rotation: in Quaternion [0.000, 0.002, 0.000, 1.000]
            in RPY (radian) [0.000, 0.003, 0.000]
            in RPY (degree) [0.000, 0.186, 0.000] 

At time 1568583863.323
- Translation: [0.000, 0.000, 0.000]
- Rotation: in Quaternion [0.000, 0.002, 0.000, 1.000]
            in RPY (radian) [0.000, 0.003, 0.000]
            in RPY (degree) [0.000, 0.186, 0.000]

Looking at the code in the odom_listener.cpp, I print updates regularly, and can see the code is getting called with a much higher frequency that I'm observing updates in view_frame or tf_echo. Any thoughts why?

#include "ros/ros.h"
#include <tf/transform_broadcaster.h>
#include "nav_msgs/Odometry.h"

/**
 * http://wiki.ros.org/evarobot_odometry/Tutorials/indigo/Writing%20a%20Simple%20Subscriber%20for%20Odometry
 * https://answers.ros.org/question/11545/plotprint-rpy-from-quaternion/#17106
 */

/**
 * on VO message from T265, updates base_link to base_frame transform used
 * by GPS and laser.  Also transforms the VO data to the base_link frame
 */
void odomCallback(const nav_msgs::Odometry::ConstPtr& msg)
{
    // Inspect incoming message
    ROS_INFO("Seq: [%d]", msg->header.seq);
    //ROS_INFO("Position-> x: [%f], y: [%f], z: [%f]", msg->pose.pose.position.x,msg->pose.pose.position.y, msg->pose.pose.position.z);
    //ROS_INFO("Orientation-> x: [%f], y: [%f], z: [%f], w: [%f]", msg->pose.pose.orientation.x, msg->pose.pose.orientation.y, msg->pose.pose.orientation.z, msg->pose.pose.orientation.w);
    //ROS_INFO("Vel-> Linear: [%f], Angular: [%f]", msg->twist.twist.linear.x,msg->twist.twist.angular.z);

    // Construct tf::Quaterion
    tf::Quaternion quat(msg->pose.pose.orientation.x, 
        msg->pose.pose.orientation.y, 
        msg->pose.pose.orientation.z, 
        msg->pose.pose.orientation.w);

    // Get RPY from Quaternion
    double roll, pitch, yaw;
    tf::Matrix3x3(quat).getRPY(roll, pitch, yaw);

    // Display converted RPY
    ROS_INFO("published rpy angles: roll=%f pitch=%f yaw=%f", roll, pitch, yaw);

    //Update tf::Quaternion with pitch only
    tf::Quaternion qPitchOnly;
    qPitchOnly.setRPY(0.0, pitch, 0.0);

    //base_link to base_frame transformation
    tf::TransformBroadcaster broadcaster;
    ros::Time currentTime = ros::Time::now();

    double secs = currentTime.toSec();
    ROS_INFO("currentTime: [%f]", secs);

    broadcaster.sendTransform(
        tf::StampedTransform(
            tf::Transform(qPitchOnly, tf::Vector3(0.0, 0 ...