Welcome to the Ranch, Thomas!
I don't know what EAP is and attempts to resolve that name only come up with things like "Employee Assistance Program".
However, I can tell you this. The
JEE UserPrincipal object (Interface) is constructed when a remote user logs in using JEE Container-Managed Security. Since it's only an Interface, the exact contents of that object are not directly knowable with the exception of the user's loginId. You obtain the UserPrincipal from the HttpServletRequest object passed in when a
servlet or
JSP is invoked. Or you can just invoke getRemoteUser() to obtain just the userID. If a user has not been logged in, you'll get back
null as the userID.
Hibernate is a general-purpose ORM and has no particular interest specifically in whether it's running in a webapp or not (in which case JEE UserPrincipal wouldn't exist). I think what you are actually looking at is not Wildfly-related but a Spring webapp object, possibly related to Spring Boot (which doesn't normally run under Wildfly, since Spring Boot normally has its own embedded webapp server - typically
Tomcat).
The secret of how to be miserable is to constantly expect things are going to happen the way that they are "supposed" to happen.
You can have faith, which carries the understanding that you may be disappointed. Then there's being a willfully-blind idiot, which virtually guarantees it.