Changeing the location of `external_control.urscript` leads to timeout of robot program

Greetings. When tinkering on another problem I copied external_control.urscript form ur_client_library to one of my ROS packages, so I could modify it if it should be necessary. I now wanted to dry-run the external control and use the carbon copy as the script, but when doing that, the robot program gets stuck.

Teach panel message: Program starts... Please wait...

In the launch file I call

script_path = PathJoinSubstitution(
        [FindPackageShare(robot_description_package_name_lc),
         "resources",
         "external_control.urscript"])

instead of

 script_path = PathJoinSubstitution(
        [FindPackageShare("ur_client_library"),
         "resources",
         "external_control.urscript"])

The file is also installed correctly. There shouldn’t be a difference right?

I’ve also noticed that the package ur_moveit_config uses another urscript in ur_moveit.launch.py, could this be related?