So it was one household, no one was an NPC. The first sim's graduation was at 10:14am and the second sim's graduation was at 10:34am. After following the first sim to the graduation (he was talking to npcs and attend graduation was not selected), I went to the second sim at 10:30am. I waited for the graduation pop up and went to that graduation ceremony (attend graduation was selected several times). It took 4 hours for the selected sim to attend the graduation and she spent several more hours inside the graduation ceremony. After the selected sim graduated her cap was gone and I sent her home. Then I switched to the other graduating sim and his cap gone and I sent him home. However, he was the only one to receive a diploma.
@boomyjo But both show as graduated properly afterwards ? It's just about the diploma/pic ?
There's also a similar report here: https://answers.ea.com/t5/Bug-Reports/PS4-No-diploma-at-graduation-but-did-receive-the-graduate/m-p/8733629# but that was just one Sim, I htink.
