To all affected by this issue.
While this thread does indicate work flows to get around this issue, a bug has been logged regarding the functionality of added an map service from ArcGIS for Server to a web map in ArcGIS Online and the lack of pop ups in Explorer for iOS. The bug information goes as follows:
NIM102374 : Attachments are disabled when an ArcGIS for Server map service is consumed, and the feature layer URL must be added to an ArcGIS Online web map to use attachments in Explorer for ArcGIS on iOS.
For now, you will need to add the service using the layer URL rather than the map server URL in order for pop ups to be maintained in Explorer for iOS. This issue has been submitted to the development team for Explorer for iOS. For further information on a fix date, you are welcome to open a case with Esri Technical Support and they can attach your case to the bug so you may follow the status of it through your Esri Global account or you have the option to email the development team for Explorer for iOS here: Explorer4ArcGIS@esri.com.
