[Ez-toc] breaks menu

Hello,
First thanks for your plugin, I am using it on a lot of my pages, and I am very grateful!

My issue:
When using the automatic insertion of the table of contents, then all looks great.
But when I use the block short code [Ez-toc], it breaks my menu.

My menu is inserted at the bottom of my pages. And then the layout and the correct position are adjusted using CSS.

As you can see on this page, the menu is broken and located at the bottom of the page.
It’s like the CSS doesn’t apply to it.

Do you have any idea how I can fix that ?

Best,
Alex