Unique field validation not working in Universal Editor

The unique field validation is not functioning in the Universal Editor. Users can enter duplicate values without any checks. Unique fields are defined in the content fragment model.

Expected behaviour

The system should validate that the field is unique in the Universal Editor. It should reject duplicate values. Or at least throw an error when editor add/patch this field in de CF.

Actual behaviour

The system currently allows any value to be entered in the unique field without validation. Duplicate values are accepted.

Steps to reproduce

Open the Universal Editor in Adobe.

Navigate to the content fragment with the unique field (ID).

Enter a value in the unique field.

Enter the same value again in another unique field (ID).

Observe that the system accepts the duplicate value.