Display Custom User Avatar

Good morning,

I’m using your great plugin for my wordpress website and I have some problems to display the user’s avatar.
First, when I activate your plugin and upload my own avatar, nothing change : the default avatar is displayed.
Secondly, in functions.php I found this part of code given by the wordpress theme to display the user’s avatar and I suppose it cause my problem : http://image.noelshack.com/fichiers/2015/31/1438249946-avatar.png

If you need access to the admin dashboard, just tell me, I will give you the login. I spent more than 1 week trying to find an issue.. if you can help me find the solution, I will give you donation.

Thanks in advance,
Regards,

Lucas Uzan

https://wordpress.org/plugins/avatar-manager/