Expression language 3.0 with Weblogic 12.2.1.4.0 not working

Question

Dears,

I am using expression language in my JSP to access Enum values, example:

<c:choose>
<c:when test="${request.status eq RequestStatusEnum.PENDING}">
<p class="status_smaller status_request status_in_progress"><fmt:message key="application.status.pending"/></p>
</c:when>
.....

where RequestStatusEnum is a simple Enum:

public enum RequestStatusEnum {
PENDING,
APPROVED,
REJECTED
}

The code above is working fine on tomcat 9.0, however when deploying on Weblogic 12.2.1.4.0, the expression RequestStatusEnum.PENDING is not getting evaluated, When replacing the expression by a scriptlet <%=RequestStatusEnum.PENDING %> it works but I want to keep using expression language.

Java version used: 1.8.0_311

According to Oracle, weblogic 12.2.1.4.0 is compliant with EL 3.0 specification.

Do you have any explanation please or any idea on how to investigate it further?

Regards