Change Payroll Number to Director

We were sent an HMRC notice to amend an employee's tax code and on the back I noticed the following sentence: Directors -- enter 'Director' in the 'Works or payroll number' space in your pay records. We only took on Payroll from July 2021 and I simply copied the information the previous payroll provider sent. I just tried to change the employee record, but apparently payroll number field "cannot be edited once a successful FPS submission is made." Employment status is already set to Director.

So, is there any way to change this at all? I've just made my final FPS submission for the tax year and wondered if it might allow me to do something once I run the EPS in the new tax year. Advice please!

Thanks in advance, Kali