Encountering Error while evaluating Life event BEN-990155

We are receiving below error when evaluating Marriage or Divorce life event. Encountering this for only specific employee.

Employee is not enrolled in two different options in same plan.

There are no duplicate entries for the dependents in the contact. I referred few community posts on the same error, however could not really conclude on the solution. Could anyone please advise.

When I ran the same life event via batch process with defaults applied. It moved to started status. Why is this happening when we try to evaluate from benefits summary page.