As @bayodesegun says, we have finally replaced the delete_model exercise for another one using a different service. This is because, after some rehearsal, we finally found out that this is an internal Gazebo issue (bug), which would require too many things to be solved. Hope you find this new Demo equally helpful and, of course, if you find any other issue or you have some feedback related to it, don’t hesitate to let us know.
Best,