Why is GithubPages not showing the page?

Question

GitHub

Question of the following nature: In my repository Vadzz/vadzz.github.io I posted several pages for examples: task7, task8, task9. Then I deleted task9, but it still shows the page on gitpages: vadzz.github.io/task9. I added task6 to the repository (Vadzz/vadzz.github.io/task6) but the vadzz.github.io/task6 page itself gives a 404 error. Does it feel like synchronization was disabled on gitpages, or am I doing something wrong?