Centerize vertically?

Trying to set up a scrolling navigation website, but having problems with sections not being centerized vertically when using “fit to screen”.

Please see the link I added and use the “Arrow Icon” pointing down to navigate to see what the issue is. The first section jumps all the way to the top, while the second is centerized. They are both identical sections.

The page I need help with: [log in to see the link]