Time Accruals not attaching to new hires

Hoping someone can help. We are having a reoccurring issue where new hires are no longer automatically attaching to time accrual banks. We have been having to manually attach running a TA125 and then manually put start dates on their banks. The problem seems to be relatively consistent with no definitive patterns. Does this sound like user error? Could the person who is inputting new hires be missing a screen? Could it be an issue with approving a new hire? Or is this more of a "system" problem. Any advice you can give would be so appreciated.