We must avoid to rely on the order in which computed fields (including related fields) and constrains methods are applied.
Due to a recent change into the ORM, the contrains on the model_id into CustomInfoTemplate is now called AFTER the recompute of the related model field into property_ids.info_value_ids
As side effect, when the constrains is called, the model on the info value is already updated with the new value and we no more know the old value....