Field validations don't get called if react-admin SimpleForm has a validate function

Consider the following code:

const validateLetterTypeForm = (values: Partial<ILetterType>) => {
	const errors: Partial<ILetterType> = {};
	//TODO: put code to validate form here
	//https://marmelab.com/react-admin/Validation.html#validation-mode
	

	return errors;
};

const LetterTypeForm2 = () => {
	return (
		<SimpleForm noValidate validate={validateLetterTypeForm}>
			<TextInput source="businessArea" required validate={requiredField}/>
			<TextInput source="letterTypeDesc" required validate={requiredField}/>
		</SimpleForm>
	);
};

We noticed that, if SimpleForm has a validate function defined (as above), the validate functions in the fields do not get called. Is this an expected react-admin SimpleForm behavior? Is there a way to have both form and field level validations?

Since react-admin 4.X.X you cannot have both validations.

https://marmelab.com/react-admin/Validation.html

They are multiple workaround to do both but none works correctly in all situations.

If you only have this <SimpleForm/> I suggest that you verify on the SimpleForm validate that the values are set and remove the fields required validate={requiredField}