You need to add a transition process step in your translation workflow in
Content Manager called TERMINATED followed by another one called REVERTPROCESS.
Additional Issue you will see:
The workflow process cannot be saved after adding the REVERTPROCESS activity. You get an error:
Invalid value for property 'ActivityDefinitions'. Activity 'REVERTPROCESS' has invalid script.
Value cannot be null.
Parameter name: s
There is a hotfix to fix the above defect so you can add the requires workflow steps in
Tridion Sites 9.1:
TM_9.1.0.29444. You can obtain this hotfix via FTP as per:
Where can I find hotfixes for SDL Tridion Sites/Web?