Column Shortcodes not working

Hello !

Please try these code format for page or post creation.

HTML:

<div class="content_onethird onethird_first">
--------------------your first content-------------------
</div>
<div class="content_onethird">
--------------------your second content-------------------
</div>
<div class="content_onethird onethird_first">
----------------------your third content---------------------
</div>

And use this CSS code in custom CSS box.

Code:

.content_onethird {
width:30%;
}

This will resolve your issue.

Thanks & Regards
Pramod Patel