Followed Artist Error

I am following Yamada Yuuya's page so I receive notifications of any new work, but I got a notification for the recent release of one of Yamada Kou's works (who I am not following) instead.

I'm assuming there is some error somewhere that has either confused or combined the two Yamada artists together when sending out notifications?

I follow BoBoBo and recently I receive a notificación of your new work, but when I want to see it, the page show me a legend like "there was a problem/ the content does not exist", my quietion is, then i can see that title more later?