Unable to make "When is the work relationship start date?" as Read only in Convert Pending Worker

Summary:

Hi Team,

Unable to make "When is the work relationship start date?" as Read only in Convert Pending Worker page under My Team

After logging in with our custom line manager role, Navigate to My Team -> Pending worker quick action -> Select any pending worker and click on 3 dots and click on “Convert” as shown below:

After that click on continue as shown below:

Our client requirement is to make the field “when is the work relationship start date” to be Read only in “When and Why” section We have tried doing it from VBS but it didn’t work. We have also tried removing all related privileges from custom line manager role but it is also not working.