All is in the title 😉
Strangely, the website is displayed ABOVE the manager sidebar. So, I cannot use the sidebar normaly. I don't understand this thing.
If you see the front-end of your website in the manager sidebar you probably need to try and reinstall/upgrade EVO.
Or try to upgrade your manager theme (/manager/media/style/).
I was afraid that this was the only solution because I was hoping to have another faster solution 😅
Thanks a lot @Graffx Design