You had the development version installed, so it may well be that there are remains from additional features planned in the next release, e.g. modified apache2 configs, cleanup may not be thorough when uninstalling the development version.
Maybe something already installed or configured on your system or a setting in your cloud environment is causing the problem. I guess the other apps installed on your system are from the test app center as well?
I just installed the app on a testsystem and can get the metadata via browser or by executing either
curl -k http://localhost/.well-known/openid-configuration
curl -k https://localhost/.well-known/openid-configuration