JSFiddle - React, Tailwind, and code Playground

HTML

<form>
    <input type="text" val="" name="mufa"></input>
    
</form>

CSS

.error{border:1px red solid;}

JavaScript

//this is not controlled by your code
$('input').on('blur', function(){
    $(this).addClass('error');
    $(this).before("<div class='someClass'>Warning Error</div>");
});

//this is your code
$('input').on('blur', function(){
    var el= $(this);
    setTimeout(function(){
        if ($(el).hasClass('error')){ 
            $(el).removeClass('error');
            $(el).prev('.someClass').hide();
        }
    },1000);
});