JSFiddle - React, Tailwind, and code Playground

HTML

<textarea style="width:100%">function should fire when the next input is tabbed into or clicked (focused), but not when changing browser tabs</textarea>
<input>

JavaScript

var times = 0;
var prevActiveElement;

$( window ).on( "blur", function(e){
        prevActiveElement = document.activeElement;
});

$('input').on('focus', function() {
    if (document.activeElement === prevActiveElement) {
        return;
    }
    prevActiveElement = document.activeElement;
    times++;
    $(this).after('<br>Focused ' + times + ' times');
}).on( "blur", function(){
    prevActiveElement = null;  
});