We have several of our web applications shared with our Open Data page. They show up in the list as expected with a little box and arrow at the end of the title telling you it will navigate away from the page. When you click on some of them, they will go straight to the application and other when clicked go to the ESRI Open Data about page. As far as we can tell, it seems that it's linked to http applications vs https. The http apps open just fine.
This brings up another odd question which is why are some of the http and others https. We switched our Organization over to https about a month ago. My understanding was that it would switch all items. The differences between which are http and which are https seem to have nothing to do with the timeline of switching the organization. Two apps that were developed about two years ago are different.
We thought it may have something to do with individual accounts but think we have ruled this out. If you would like to test this out, here is our open data page...
Thanks for any advice, information, or best guess you can throw my way!