I eliminated the ipynb checkpoints and uploaded the files again and the tasks failed in the same way. I do not see anyone else having this issue, so I do not know If i did something wrong, but it seems to be somthing with the unix:var that is being used for the DockerOperator and that is not something that is defined by the students.
Hello everyone,
You are right. The docker_dbt_command task in the DAG seems to have an issue. I have reported it, and I will inform you as soon as I get any updates regarding this issue.