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Can you confirm that neither the exposure scale, nor the film counter light up?
I'm not aware of custom settings on EOS film cameras that disable critical parts of the viewfinder display. I assume that the right-side viewfinder display is a physically distinct LED display from the bottom bar. If nothing shows up on the right-side of the viewfinder, it's possible that this display has failed entirely, or there's a contact issue between the display and the camera's main/flexboards that control the display.
I have had one segment on a viewfinder display fail in an EOS1 film camera, but that was a single segment.