Thank you for your post.
I am unable to replicate the issue with the slide control panel with FileMaker Pro 14.0.1 under Windows 8.1.
I am having difficulty understanding the pop-up menu issue you are reporting. Is the pop-up menu part of the slide panel?
It would probably be best if you sent in a clone of your file so I can try it here. Check your Inbox at the top of this page for instructions where to send the file.