[update] copy o2m fields

models/export_journal_type.py

@@ -15,7 +15,8 @@ class ExportJournalType(models.Model):
     fields_ids = fields.One2many(
         comodel_name='export.journal.field',
         inverse_name='export_id',
-        string="Champs"
+        string="Champs",
+        copy=True
     )
     is_header = fields.Boolean('Header', default=True)
     company_id = fields.Many2one(