Parts of hidden button showing on Publish Online document

Hi everyone,

I have an issue where near the edges of one button there is a small section of the hidden buttons showing 'underneath'. 

As you can see below there are some hidden sections (that would show when clicking a button to reveal them), but these 'edge's are showing all the time! The bits that are showing are not covered buy anything, although the do dissapear when I delete that grey segment, any ideas as to what might be causing this? Also worth noting this only happens on 'Publish Online' if I export it as a pdf file there are no issues!

{Renamed by MOD}