After deleting a fork of a fork of master branch, when going to the page for creating fork again, it shows a 404 error

I using
After deleting my a fork of another fork of main project.

On the project page main project, when I click on the “Fork” button.

It sends me to the page with a 404 error.

On this page address bar contains a link to my fork that has been removed.

But me need page, here I can forked master branch main project.

(Offtop) I can restore my fork (with another guy’s files changed that I don’t need), but me need fork main project. How it can, if he did 404 page? (Offtop)