Elegibility Profile "Continue participation" Option

I'm very confused by some strange situations that occur in the benefits module.

One of them concerns the "Continue participation" option.
The eligibility documentation does not mention this parameterization option - link below.

https://docs.oracle.com/en/cloud/saas/human-resources/faibf/eligibility-profiles.html#Defining-Eligibility-Criteria

Anyway, I did some tests on the Client's database and, apparently, if the profile had "Continue participation" and we used that profile for eligibility for a plan, the plan became eligible for all employees, regardless of whether they had already been enrolled in the plan or not. I didn't see any sense in this behavior.