522 on non-custom domain (pages.dev)

Hello, I'm uploading a file deploy to do some testing, and for some reason i'm getting a 522 error on my my-project.pages.dev domain. My understanding is that this usually only happens on pages when you point a domain at it, but do not add it to custom domains. I have not added a custom domain though, this is from directly accessing it at my-project.pages.dev https://cf-adapter-test.pages.dev/ any idea why this is happening?