Project Managers and Resources with EDIT access to Project Properties page cannot edit Project Status.
CA PPM SaaS and CA PPM On Premise
It is missing the Access Rights required to edit Project Status field.
One needs to assign Groups and Resources with 'Project - Approve - All' rights to allow them to Edit / Approve project status.
NOTE: This includes 'Project - Edit - All' right which allows users to edit all projects excluding secure sub-pages.
Refer - Project and Portfolio Management Access Rights: