I sent two adult passport renewal, one went to Liverpool and the other went to Durham.
Here’s my timeline
For Liverpool:
Application Submitted: 24 Feb 2022
Application Received: 24 Feb 2022
Documents Received: 5 Mar 2022
Application Approved: 5 Mar 2022
Passport Printed And Sent 7 Mar 2022
So It took only 11 days
For Durham:
Application Submitted: 24 Feb 2022
Application Received: 24 Feb 2022
Documents Received: 11 Mar 2022
Application Approved: 15 Mar 2022
Passport Printed And Sent 17 Mar 2022
It took 21 days
Apparently the reason why Durham took so long was because all international passports are also processed in Durham and it’s also their main office. This is according to the phone operator when I called them.