Can’t turn on dark mode (resolved)

I’m using iOS 18.1.1 on an iPhone 13. I’ve been able to switch between light and dark modes before, but now when I try to switch to dark mode the button/toggle just doesn’t work/acknowledge- it quickly flashes as though to say “yes I know you pressed me but so?”, and I’m stuck in light mode.

Edit: that was still odd, but it seems to have fixed itself, I think…