drop down menu screencasting

I published a Cp8 responsive project.  When I watch the published project, I notice that on slides where I screencast selecting an item from a drop down menu, a portion of the drop down menu appears on the screen.  This was not present when I "previewed" the project.  But in the published version, these extra bits are present.

In this example, the pointer is clicking on POC Responses.  And below this, an extra bit of the screen appears.

Any ideas as to why this is happening, and what I can do to prevent it from happening again?

Thank you!