Drag and Drop, slider and drop menu interactions not working

Hi. We have several courses that use drag and drop, drop down menus and slider interactions in them (in Articulate 2). We are finding that these interactions are not working for all the learners all the time. Some people can complete the course, while some cannot-there is no rhyme or reason as to who can and cannot. For most of the users, however, the issues are occurring while using an iPad. 

The issue that is happening is that when the user moves the drag item to the drop target, the entire screen/slide moves, and they are not able to get the item to the drop area, because the drop target has moved off the screen. (The same issue is happening for the slider and drop down menu, if there is a longer list to choose from.)