Okay, I think it was a coincidence with the formatting. I just noticed the other thing I changed at that time was zooming up from 100% since you mentioned zooming in Pages, as I wanted to see it and TextEdit together. Here is TextEdit:
So this what Apple thinks the cursor should look like (at least outside of the iWork division). We’ve cut that down as much as we can, but evidently anyway it is supposed to get massively fat when zooming.
Zoom is something I ordinarily never mess with in Scrivener since the font size can be arbitrary. Might as well just make it bigger if you want bigger text, as the compiler can fix all of that. You get far fewer display glitches and bugs in my experience, as the text engine’s zoom code is pretty fragile (the amount of duct tape we have on top of it to fix known problems may well cause other problems too).
But yes, I did have a dim memory of having seen this before, and found the thread on it. As I suspected, this can’t actually be fixed by us since its coming out of the text engine that way. We’d probably have to switch to how TextEdit zooms, which would be infuriating after about 40 seconds of writing. 