When first starting a new game, it worked fine, but I wanted to change something on my player character, so I backed out to the main menu. Now, every time I start a "default" game, it skips the starting slave menu, even after restarting the game.

Edit: I must be missing something because even deleting the appdata folders and reinstalling it all didn't fix it.

Did you complete the starting quest? You don't get your first slave right at the start of the game, only when you join one of the guilds.

I thought it originally let me *design* them before that at least. Maybe I'm just very confused and getting it mixed up with how the first game did it + how sandbox mode does it?

Default preset only lets you design first slave later.

You may have been playing Sandbox the first time?

^

" Now, every time I start a "default" game, it skips the starting slave menu, even after restarting the game."

I agree with JJJ and Author. Sounds like Operator error rather then a glitch.  Default,  starts slave creation after siding with a guide, Sandbox throws it at you after protagonist/main creation.

Yeah, I just misclicked before and did Sandbox first time without realizing it. My bad >.<