flipbook moving out of (and breaking page html flow)

Hello,
Weird behaviour on pages displaying flowpaper flipbook : the default widget sidebar is taken out of the content div, and appears under the content instead of being beside.

Here is the html code of such a page, plugin activated :

<main id=”main” class=...>
	<header class=“page-header”>...<.header>
	<!-- .page-header -->
	<div id=”content-wrap” class=...>
		<div id=”primary” class=...>
				... [ flowpaper iframe ] ...
		</div>
			<!-- #content -->
			::after
		</div>
		<!-- #primary -->
	<aside id=”right-sidebar” class=...>...</aside>
	<!-- #right-sidebar -->
	::after
</main>

And the code of the same page, plugin deactivated :

<main id=”main” class=...>
	<header class=“page-header”>...<.header>
	<!-- .page-header -->
	<div id=”content-wrap” class=...>
		<div id=”primary” class=...>...
			... [ flowpaper iframe ] ...
		</div>
		<!-- #primary -->
	<aside id=”right-sidebar” class=...>...</aside>
		<!-- #right-sidebar -->
		::after
	</div>
	<!-- #content-wrap -->
	::after
</main>

What can I do to maintain the correct displaying of the sidebar on the side of the content, and not after it ? ie the <aside> block inside the <div id=”content-wrap”> ?

Thank you.