There is a conception issue.
For now, whatever the form question type, we return the same model with all the model items of all the form question types. So a "simple question" has in its model the model of all computed questions + the model of a matrix question + ...
See FormQuestionFactory.getModel

The type of a question is hold by the model. It should not. It should be stored as ametys-internal:type.

Exception: quid of computed question ? same type but model could depends on the source type