Open enrollment life event ended the election and throws error though the person is eligible

Open ernollment life event has ended the election for one person and throws electable choice error but I understand that usually if person fails the eligibility this error happens. But in our case , the same data is copied to TEST due to cloning  and to confirm whether it is an eligibility issue we tested the same in Test instance by unprocessing and reprocessing the Open event for this person.We also verified that this person is eligible.

—>If the individual is not eligible, then even when we reprocess the life event, an error should be thrown. However, instead of an error, the election is being carried forward correctly. We know that by reprocessing, the election will be carried forward in PROD as well, but we are unsure