A small error in a repeated task deserves a change to the task, not only a reminder to be careful.

When the same small error keeps appearing in a routine task, the person is rarely the variable. Attention drops on anything done often, and telling someone to concentrate harder is a request rather than a change, so the next mistake is already scheduled. Care is not a mechanism. Altering the order, the layout, or the point where a check happens actually changes the odds.

Instead of issuing another reminder, move something: change a default, reorder two steps, make the wrong action awkward and the right one obvious. Then watch for a month to see whether the error comes back.