How to delete link to next post on my portfolio page?

Site URL: https://vickyliszew.com/

Hi all! Does anyone know how to delete a link to my next post on the bottom of my post? (Please see attached image)
Also I noticed that this link only appears on the first post, could someone help explain that?

https://vickyliszew.com/home/usability-evaluation

Much appreciated for your help!

Vicky

Add to Home > Design > Custom CSS

.item-pagination[data-collection-type^="portfolio"] {
    display: none !important;
}