Description: If the only card in an opponent's graveyard is one that they can somehow "cast" (exhume, flashback or similar ability), it will show up next to their hand (correct) but the graveyard itself will be empty and you can't click on it to bring up the screen of (one) card(s) in it.

STR:
Have opponent with a flashback spell in their graveyard.
Look at their graveyard and note that it is empty.
Try to click on the graveyard to bring up the graveyard view screen

Actual result: No cards are shown in the graveyard and the graveyard view screen can't be brought up.

Expected result: Recurrable cards show up both next to opponent's hand AND as part of their graveyard.

Note: I believe this also happens if it's your graveyard with the single card in it.