Cannot book annual leave despite having enough balance

Hello,

A staff member has recently begun to receive the following error message when attempting to book annual leave:

"You can't record this absence because your balance for plan Annual Leave will fall below the configured minimum for this type of absence."

The error message occurs whatever date is selected.

This appears to be the only staff member that is affected by this error message.

In My Client Groups > Person Information > Staff member record > Absence Records > Plan Balances > Annual Leave the staff member has enough balance remaining to take the leave periods. There is no open ended sickness on the record.