This problem is in Wildfly Core, but manifests as an issue with EJB's in WildFly full.

Given the following class/interface inheritance structure, the interface method doMagic could not be called from a remote view, even if there is a default implementation as given in the mixin interface. A local call works, but the remote call fails with a message like

org.jboss.invocation.CannotProceedException: INV000002: Invocation cannot proceed (end of interceptor chain has been hit)

Example code:

@Remote
interface MyEJBInterface {
   void doMagic();
}

interface MyEJBMixin extends MyEJBInterface {
   default void doMagic() { .... }
}

@Stateless
class MyEJBBean extends MyEJBMixin {
}

The problem is inside the fix for WFLY-4354 bug, which checks only for the default method implementation in the interface declaring the method the first time but not in other interfaces.
A example is attached and I will submitt a pull request with a fix.