When duplicating a project, every task linked to the project is duplicated too but the link between sub-tasks and their parent task is not updated thus they are left linked to the task of the original project. opw-1937371 closes odoo/odoo#31154
When duplicating a project, every task linked to the project is duplicated too but the link between sub-tasks and their parent task is not updated thus they are left linked to the task of the original project. opw-1937371 closes odoo/odoo#31154