From the documentation about the [single_affiliate title=”” size=””]
title : The title of the Review post you want to display.
size : The available options are small,big. The small size usually fits better in a widget area and inside a column and the big size fits better in whole content width.
Are you sure you are using the shortcode correctly?
We haven’t noticed any bug in this part in any of our clients.
The only thing I can think of is if you noticed that the bug in “Affiliate small info” maybe you left a html tag without closing it in this field and it’s causing the problem.