I was learning ROS2NAV2, following the documentations, when I launched the file, The ODOM TF started moving itself in the space

Question

I am learning ROS2 NAV2, created a URDF file, it runs perfectly in Gazebo...But after 20-25 seconds the ODOM Tf automatically starts moving upwards or sometimes goes down it the grid, For the code, I have literally copy pasted from the documentations twice, getting the same issue. Please do help if you have the solution. ODOM TF moves away from the robot automatically Rviz shows no error

I tried to go through the documentations and copy paste my code from it. But tbh I feel there is some issue in the code itself...