how to disable transition buttons on the Approval page

We have SMAX 2022.11 running in our environment

On the Approval page, once a Change Request (CR) is approved, transition button 'Reopen' is displayed. Additionally, once a CR is denied, both 'Reopen' and 'Approve' buttons are displayed.

why these buttons remain enabled after a CR is approved or denied? Any specific reason?

Also how can we disable these transition buttons on the Approval page?