One of my Sims lost his job for no reason

I'm a rotational player and have this one Sim who's in the criminal career, Boss branch. Last time I played him, he was totally fine, had just added a cellar/dungeon to  his house, was enjoying himself with his Misfits club, was doing great in his career.

Yesterday, I checked back in with him again and noticed he no longer had a job. I have no idea how that might have happened. I know he didn't quit, and I stick with every household for a whole Sim week. Even if I have to switch mid-week, the Sims concerned never lost their jobs. He also didn't get a notice from his employer, so I'm pretty sure he wasn't fired, either. 

He was able to choose the criminal career again and entered it at the Boss branch, too, so he doesn't have to start from scratch and lost maybe one tier. No idea why the game allowed that because he never went to college and doesn't have a degree that enables him to enter at a higher career level.

Any ideas what could have caused this or has this happened to anybody else? My best guess is that it's a bug courtesy of one of the latest updates, like the bug that prevents promotion when a Sim has the entrepreneurial trait.