Goal plan not assigning correctly

Summary

Goal plan not assigning to eligible employee

Content

I have an issue that is happening intermittently across the employee population with no pattern. I have the current year goal plan scheduled to mass assign daily with a blank effective date. The goal plan has successfully assigned to 99% of the population however I see a few people reporting they are not receiving the goal plan. 

I have run the goal plan eligibility on these employees and it will show that they are eligible for the plan however they are not being assigned during the daily scheduled process. In these cases I have added them individually to the goal plan job and the job assigns as needed. The issue is that I have to individually add and remove people as the issue is reported.