Hi,
I consider using plugin for my client’s site. But first I test on my local machine.
There isn’t public link yet. I can send you video from my local machine screen.
I guess that the following line of code is causing this effect.
jQuery('body, html').animate({scrollTop:$topErrorPosition}, 'normal');
This code from click submit button event handler.
Fancybox create wrapper with fixed position and scrolling html or body has no effect.