There appears to be an issue with the generated redirect_uri. The same org, client ID, and secret work just fine under 2.4 but get the attached error when reconfigured under 2.5. 

I did notice that this in the URL when I try to log in via GitHub "redirect_uri=http://aap-aap.apps.ocp.m...." that it defaults to http. Correcting this to https does route back to AAP and prompt for authorization (github side) but fails to login.