Can a already fixed diaphragmatic hernia cause later on respiratory problems?

Possibly: In the case of congenital diaphragmatic hernia, there is usually some degree of pulmonary hypoplasia (lung underdevelopment) which can lead to chronic pulmonary problems. In addition, there is some risk of hernia recurrence which would cause pulmonary problems from the abdominal organs herniating through the diaphragm into the chest and compressing the lung(s).