The Projects page opens on the Editorial feed with the sort set to Magic, and Magic is a shuffle rather than a ranking. It drops you at a randomly chosen page of the editorial list instead of the top, then carries on downward from there. That is why the same page shows different work each time you open it, and why the newest editorial project is rarely the first thing you see.
Nothing is being hidden from you and nothing has been reordered by an algorithm reading your behaviour. The order underneath is fixed. Only your starting point moves.
Magic picks one of the first twenty pages
Editorial pages hold 40 projects each, and Magic chooses among the first 20 of them. So a visit can begin anywhere in the first 800 projects of the list, and everything above the page it lands on is skipped for that visit. If the page it picks comes back empty, it falls back to the first page.
Underneath the shuffle, the order is newest first
Take the randomness away and the editorial list is ordered by the date the project was created, newest first. That is the order every other sort starts from.
The other sorts turn the shuffle off
Open the sort control and choose Most Recent, Most Popular, Most Discussed, Top Rated or A-Z. Each of those starts at the top of the list and stays put, so the feed becomes stable and repeatable. Most Recent is the one to pick if you want to see what was added since your last visit.
Your choice is written into the page address as a sort parameter, so a link you copy or bookmark while a sort is applied keeps that sort.
A reload can hand you the same page anyway
Feed responses are cached for five minutes on the server, and your browser tab holds its own copy for two minutes. Inside those windows the same page number returns the same projects, so refreshing does not always reshuffle.
Signing in reshuffles the feed
The sign-in box that appears after a few scrolls reloads the page once you sign in, and that reload draws a fresh random starting page. You do not come back to the projects you were looking at. See the feed asks you to sign in after a few scrolls.
Do not scroll back to find something again
A project you saw once and did not open is hard to reach by scrolling, because the feed will have moved. Use search, or open the author's profile, or bookmark the project while you have it in front of you. Bookmarks are on your profile under Saved.
The other feeds do not use Magic
All Projects, Trending and Award Winning all start at the top of their own list. Magic is only the default on the editorial page you land on first, so if the shuffling is the problem, moving to All Projects solves it as well as changing the sort does.