When this happens, you need to check if the user has a Fixed Term End Date set.
To check this, follow the steps below:
Click Access Button
then click Employee.
Click the relevant employee then click the Employment tab.
Check the Fixed Term End Date tab.
πNote: Anything after the Fixed Term End Date won't be counted as public holidays and you won't be able to amend the duration of it.
To solve this, remove their Fixed Term End Date.