We have configured Project time card approval, but now client doesn't want to use the projects now

We have configured Project time card approval, but now client doesn't want to use the projects now. When we make project field as not mandatory or remove the project field or keep the project field blank. The workflow approval for project time card approval is not working as expcted as per the configuration and all the time cards are getting auto approved. Please guide us on how to achieve the workflow configuration if the client doesnt want to use the projects field in time card. Consumer set is also setup for projects, absence management only and not for payroll.