Taxable benefit calculation Issue when employee retiring

We have an employee who is flexibly retiring on 31/7/26 who has a salary sacrifice car.
I've entered the available to date as the 31/7/26 but unlike when we were reporting P11D's and the end date correctly apportioned the tax,
when we ran a quick pay it seems that the component is taking the remaining tax for the year from the July salary.

Are you able to advise what we need to do to ensure the correct taxable benefit is calculated.
We will need to know how this works because there will be employees who have car loans which end part way through a year.