The Railway GitHub App must be installed on the GitHub organization itself, not just your personal GitHub account. Go to github.com/settings/installations, find the Railway app, click Configure, and ensure the organization is listed and has access to the relevant repositories. If the org isn't listed, an organization admin needs to install the Railway GitHub App from the org's settings at GitHub → Organization Settings → GitHub Apps (or Third-party access)

I was having a similar issue earlier today. After disconnecting everything and reconnecting I got a "Bad credentials" error under the Branch section of the deployment settings. Eventually that went away (a cache issue within Railway I guess), but deployments started failing with unknown errors. I tried creating a new environment with a new service to test with, but when I attempt to deploy I get a toast in the bottom-right saying "There was an error deploying from source." I'm wondering if there's either some internal downtime within Railway right now, or maybe an issue connecting to GitHub on Railway's backend.

It looks like things are working for me again now. I'm no longer getting the "There was an error deploying from source." error message, and my deployments appear to be progressing normally.