I am not sure this is the exact same problem, but I didn't want to needlessly start a new thread. I am able to load WP articles within the WP app about 90% of the time when I launch them from the notification center. It seems to me that the majority of those articles that fail to load are advertisements, like "Deal of the Day" posts. This has been an issue for a long time but I have only recently figured out the common thread. Like the original poster said, if I open the article from launching the app via the tile, then all is good.