I found other topics about it but their solutions didn’t seem to help.
I have a folder (“Project”) with a page in it (“Zeit”). on the published site the link to this page gives me a 404 error despite the correct link. If I type the URL manually (https://www.thealex.design/project/zeit) the page exists. And you can see at the bottom of the browser, the url of the link is the same.
Thanks @uoasman
The link is the title of the project in the card (class “Project-name”). The side menu is more of navigation within the page. I also publish to both domains every time I make a change and did it once again just now. Still having this problem.