Why is the max memory calculated wrong by the jvm using the maxRamPercentage in an openshift environment?

Question

I am in an openshift environment. Here the pod resource configuration:

resources:
  limits:
    cpu: '4'
    memory: 16Gi
  requests:
    cpu: '2'
    memory: 8Gi

Here the jvm java_options:

-XX:MaxRAMPercentage=50.0

I would have expected that the maximum memory is calculated to 8 Gb but opening the wildfly console I see 7282 MB

Why is the max memory calculated wrong?