Hi @MeineLiebeAxt ,
I had the same problem.
The laser scanner mounted on the robot in the rosject is a 360 degree laser scanner.
So 0/719 is back, 180 is right, 360 is front, and 540 is left.
Refer to this post: Incorrect Robot Scan Values in ROS Basics Course - Wall Follower Robot / TurtleBot3
Just do a rostopic echo /scan -n1 to get more info about laser scanner values if you are unsure of device properties.
Regards,
Girish