Drag & Drop Triggers Not Working When Too Many Used

I haven't been able to find anything regarding this issue in the discussion boards...but I can't be the only one that has had this problem? I am creating a virtual lab that requires users to use drag and drop to interact with their lab bench and materials. Things work okay when I preview a slide or a certain scene in Storyline, but when I preview the entire project or test it in Review 360/SCORM Cloud, etc. certain drag and drop triggers don't work. The triggers that don't work tend to be "later" in the story. I've had this issue happen in another project as well, and ended up having to remove ALL of the drag-drop triggers because when the trigger-in-question was modified to get around the issue, the next drag-and-drop trigger became stuck. I don't want to have to do this to my current project - so any help is appreciated! Thanks :)