I've been using the beta of iOS 11 on my iPad Pro for a little over a week, and it has been solid, but today I noticed my first "bug." I have Todoist and Outlook configured in split screen and for some reason the top line of my task list is not displaying. When I slide the list down, the rubber band effect causes the list to spring back and the top line goes under the title of the window. I fixed it by sliding the Todoist app nearly all the way to the left and then the window adjusted, slid it back and now the top line displays as it should. It appears that Todoist has an intermittent rubber banding issue.
I've noticed a navigation issue between story pages in 1999. If you go to the July 3 page and click the right navigation button, you will end up at a titleless page on which the right navigation button is not active. I think the issue is caused by when I create a title for a story. Everything appears to work as it should if I create the post in the immediate edit after creating the story, you can't add a title until a post is saved.
What is happening is that the original page is created using the numerical page number assigned to a titleless post and then navigation link of the previous post is updated to point to hit. Next, when I add a title a new page is created using the title name for the page name but the previous page is not deleted nor is the navigation link updated again. The situation doesn't appear every time, so I have to pay more attention to the exact sequence that causes it.
A related issue is apparent if you look at the 1999.io Bloggers river because you see entries of my posts, first when they are created without a title and later with a title. Andy's river must be getting a ping the instant I post an item because the RSS feed entry does get updated after I create a title.