Hello,
when using screen customisation, it is possible to set some field mandatory only for certain state.
But, when element get the state, field with combobox are automaticaly set to the first value of combo and then, if user don't care, the value is false most of the time.
For user input, the behavior is correct (can't reach next state without setting the value), but for combo, no message is displayed.
I thnik that best behavior is to get alert message for all type of field rather than choosing the first value.
Regards,
You will face this behavior only for existing items, already in the concerned status when you add this mandatory behavior.
For items not yet in the status where the field is mandatory, when status is changed the mandatory field is still empty, so required to be changed by the user before saving new status.
The the behavior you face is just temorary.