Dear @jpdl
a link to your website is helpful. Then we can have a look.
When Fullscreen Slider is active, all rows will get stretched to the height of the browser and the content will be vertically centered.
Dear @NR
well. Please understood that people put a lot of work into that product.
You were in a very comfortable position to use it for free until now.
You are not forced. You are always free to use another Wordpress theme.