How to reset the customized project home page to default appearance ?

I'm working on a test environment , and when I log in Project Financial Management page I face the following issues

1. get the default page theme changed to have search fields in the top not in the corner as usual
2. have the create symbol as LOV
3. when click on a project I don't get the actions list to select which page to go " like Manage Project Budget " , I get the system directs me to project overview directly

My Requirement is how to reset this page and also by which tool in sandbox this behavior was executed ?