Multi-step form validation and server-side validation

After server-side validation, I am calling forceUpdate() to update the UI. 
But, this isn't "wired" to the FormSubmitClickEvent isValid - or at least not in the same time frame as the onStep function. 
Is there a way to tie server-side validation in with FormSubmitClickEvent isValid? Since this process is asynchronous, I'm guessing it will be challenging. 
 
... Called after server-side validation to update the UI - this works
setTimeout(() => {
formRef.current.forceUpdate();
});
 
... Called when user clicks the "next" button on the multi-step screen
const onStepClick = React.useCallback(
    (event: FormSubmitClickEvent) => {