So I created a new Connected App in Salesforce - in a sandbox environment. In the app's settings I enabled OAuth with Full access and set the Callback URI to
This was about a week ago, so I know that the Callback URI has had plenty of time to fully propagate. However, if I try loading the auth URL it returns this error every time:
These are the auth URLs I have been trying:
Is there perhaps an entirely different auth URL to use for sandboxed environments? The error seems misleading since the URI I'm sending in my auth request does precisely match my configuration.