The plugin does not generate any <br> empty characters – that is what I am trying to say. That is not coming from ajax search pro, please understand that. There are also empty paragraphs injected to the final plugin code as you can see on the screenshot. None of that is coming from ajax search pro.
Empty lines are only present as part of the HTML code formatting, as /r/n characters, which is perfectly normal. The problem is, that these lines are converted further into HTML by the widget handler, that is a huge problem.
This conversion usually happens when a TEXT widget is used as a container for HTML or shortcode like in your case – where the widget output code is further processed to add paragraphs and empty lines as HTML.
The reason why it seeming is okay on the previous release is, that there are fewer lines of indentation used because we have changed some attributes on the form controls.
To test, you can place the plugin shortcode anywhere into a post content or into the template directly – you will see the output will be correct.
To resolve this, just switch the widget container to a HTML or a shortcode container and it will be immediately resolved.