It seems as though validation (or form state) is not properly re-evaluated and updated when a field is removed from a field array. Due to this bug, a call to form.validateAllFields ("change") was ...

Of all the hats JavaScript can wear, its form-processing features are among the most sought and used. Learn how to use JavaScript for form processing, validation, and more.

I wrote an article on forms and validation with React JS, Nailing that validation with React JS, the result of that was this extension. The main concept is that forms, inputs and validation is done ...