Everyone in my replies telling me it showed me the correct result for 8.1/3: yes well done, I’m so glad you’ve figured out what caused the bug, your badge for being a very special boy who is cleverer than the other people in the replies is in the mail. It’s still a shitty sloppy bug in a basic function of a headline feature of the OS that breaks something that used to work just fine.
And no, it wasn’t a split-second UI glitch, it stayed the way it appears in the screenshot until I exited, did the same thing when I tried it again, and only on the third try did it update properly.