How to export current theme from Infinity?

So this is an Infinity question, but maybe you guys will know. I have an active theme set up in Infinity (for Reddit), but I think it's not saved? Or maybe it's broken, idk.

There's a theme "nice" under my themes, but when I preview it, that's not what the app looks like. "Nice" is also listed as an active theme for dark and amoled themes, but that's the same thing. And when I export it and import to Eternity, again that's just whatever the nice theme is.

I know I fiddled with the themes years ago and I don't remember how I got the app into this state. Any idea?

(When I apply the nice theme, it changes the look and I don't see a way to get it back except for a complete settings import, which works.)