The "No-roleowner" configuration has to be defined at the initiator level and not at the stage level - as there's only 1 stage.
The application will look to find an approver at the stage, before it catches the detour condition, so if the approver is not found, then it calls the Escape.
You should define a condition at Initiator, to move the request to 2 different paths -
1 - for path with role owner.
2 - for path without role owner.
The parameters 2038 is better explained in the note 1757735.
All the best!