The SSR debug mode is always black.
branch: srp/devs
EDIT: Turns out the debug exposure needs to be overridden in order SSR to be seen. I would treat it as UX bug, users have to understand what is happening and then know where to find the Exposure override.
Maybe we could improve the behavior? For example use the cameras exposure that is displaying the debug? So that the the SSR would be instantly visible and user could still boost or lower the compensation further.