In-game skin doesn't match what I have equipped

As of a few days ago, my skin keeps showing up as one of the defaults, Ari, despite the fact that my current skin is a custom one and I'd never even played as Ari before being forced to do so. If I switch my skin a bunch of times before settling on the preferred one, or just spam the "use" button, there's about a 50% chance that my in-game skin will right itself the next time I open a world... for just that session. Then it will revert back to Ari, even though I haven't changed anything.