We have followed this steps:
Registered a developer app on wordpress.com (oauth2)
Tested oauth2 auth flow with wordpress.com blog, it worked
Installed latest wordpress on my own domain
Installed Jetpack on my own domain
Connected jetpack to wordpress.com, it worked
Tried to authorize client to post on my own domain, it failed
The flow starts with this url:
When trying to authorize the client it asks which blog I want to connect, then I select the one on my own domain and I click to "Authorize".
The url at this point is:
Then it asks the login in my domain, which I think is a bit strange because I already connected my blog to wordpress, when I login with admin account it just shows the admin panel main page.
I also tried disabling all plugins but jetpack.
Any help would be appreciated.