Hey.
from what I would guess by looking at your page, it's because you have no download available. If there is no download, the page also won't show up in the search. You may also have gotten an email about that after creating the page.
Other reasons could be that you have not set your page to being published to the public. If it is still shown as 'Draft' at the top bar, it is only available to people who have the link to it.
For the Devlog, it actually should appear as far as I know. You can check if it is set to published, as well. Other than that, keep in mind that new Devlogs normally only show up under the 'Most recent' tab until they got interacted with (Like getting likes or comments).