e.preventDefault() disabling tabindex html form

Question

I have a simple 3 step html form for registration procedure. And I'm using bootstrapValidator for validating regexpr. The problem I'm facing is on submission of each step form I'm running a success function according to bootstrapValidator docs like this

.on('success.form.bv', function (e) {
    e.preventDefault();                                     
});

And I need this function because I'm making an ajax call in that success function. But this is preventing me from using browser inbuilt tab index feature to change focus from one input to other. I even used "tabindex" attributes but that's not helping. So how do I have the above success function and use tab index feature?

Can anyone help me solve this? I'm all ears. Thanks