Bug report

Required Info:

• Operating System: Ubuntu 22.04
• ROS2 Version: Humble
• Version or commit hash: 150dd6b
• DDS implementation: mw_cyclonedds_cpp

Expected behavior

I set vx_max = 0.5 in file parameter, then when it is running, I change the vx_max to 0.3. I use parameter get to show param, it shows vx_max = 0.3 but the robot runs with vx = 0.5.