It happens when the arrow to go back to the previous entry is clicked (from any page in the entry). What's odd is there is absolutely no transition, and nothing in the console whatsoever. Re-entering the game shows that everything saved properly, but it's still odd.

Can't reproduce.

Now it does it for the Rod of the Bifrost entry, and the Elven Mana Lenses entry is fine...

Also doesn't happen every time...I've been trying to capture a video of it, but it never happens when I do this.

EDIT: Got it. https://i.gyazo.com/6b134f2333820a00509fef8d483dbd3a.mp4

I have the console open to show that absolutely nothing happens, it doesn't even save until re-entering the single-player menu.

It hasn't happened again, but it may be that the problem moved to another entry again. If the problem re-appears, I'll add a comment. But for now it appears to be gone.