I trust Queue job will give clear picture about the issue, however,
Create a new project and isolate whether the issue is with that project or all the projects.
If the issue is only with that project, check-in the project in PWA, later edit & save again, check the status.
If the issue is with all the projects, check another EPT, check whether the EPT is associated with Project templates. If possible remove the Project template and check again.
Otherwise, Open the plan in Project professional, save and publish. check the status.
Cheers. Happy troubleshooting !!! Sriram E - MSFT Enterprise Project Management