I followed the guide here, but I did not see it update
If you’re using an unmodified version of the default theme, Casper, your theme will be automatically updated
Like, maybe you don't see an update because it's already automatically updated itself?
I'm using the "Headline" theme (v1.0.0) and figured it would update itself. I also have Casper installed (was using that before) and it's at v4.1.0 so it seems it's not updating automatically for me either.
Edit: I see what you meant. Updating the theme through the admin panel does not work. I manually uploaded the Casper theme and the version changed from 4.1.0 to 5.2.3.