If you experience this, reset the user's access rights by following the steps below:
Click Access Button
then click Employee.
Select the relevant employee record, then click Overview.
Click Edit Access Rights and select Remove Admin Status.
📌Note: This will remove all the access rights, including the default ones, so take a note of the access the employee has before removing them.
Click Save.
Go back to Edit Access Rights, and give the user access to the areas that were selected before being removed. This will now allow you to update the field and to save the changes.