In Symfony 2.8.8 if AvanzuAdminThemeBundle is placed after TwigBundle in AppKerenl.php $bundles its overwrite default Symfony 404 error page as you can see in the attachment.
If it's placed before TwigBundle i get default 404 symfony error page as expected.
This issue occure only in urls that begins with "/admin" if you don't have route that match "/admin" prefix.
