Weird behavior of steering in Isaac

Hi, people.
I wanted to ask about the issue I am having with the weird behavior of my custom robot.
The robot has 4 driving and 2 steering actuators in front.
I am sending driving (0.1m/s) and steering (0 deg) commands in this video.
So, I expect the robot to follow the straight path without moving its steering, but I don’t see this behavior.
For dumping and stiffness values, I am using 1e12 and 1e8.
Could you please give me the tips on the possible reasons for the malfunction?
I really appreciate your help!

video: Screen Recording 2024-04-13 at - Google Drive

USD file: ex1_camera.usd - Google Drive