Ok just had a look....i'm not 100% sure what the issue is but I can hazard a guess based on what I can see.
What i'd do is duplicate your site (so you have an unedited version) and try setting your section positions to "Auto" rathen than "Relative", and do the same for your inner sections. Remove an padding, positioning etc you've done to make things vertically centered in their sections. Although it doesn't look like it in the Webflow designer view, FullPage actually centered everything vertically in each section by default.
A few of your internal containers are also set to absolute position which might be contributing to the script not being able to find the correct section to scroll to. Again, presuming you've done this to center your contents within each section...just switch these to "Auto" and let FullPage handle it