Thanks for reporting this, this is currently expected behaviour. To perform PR decoration we need to have the link to the GitHub repository for that SonarCloud project. This link is not provided at the moment when the SonarCloud project is created by performing the first scan.
We currently have no plans yet to support your use-case. I suggest to create a post in Suggest New Features if this is something you would like to see.
I do not think this thread is related to your issue.
Just to make sure I understand correct, this means that only projects initiated manually on sonarcloud.io, by an organisation administrator will have PRs decorated? Or is it possible to enable PR decoration in some other way? I.e. is it possible to enable PR decoration after the project have been initiated on sonarcloud, by adjusting settings, without having to delete it, and re-create?
Currently this is not possible. We do have this functionality on the roadmap, but we can’t specify an exact timeline yet. You can follow this ticket to get updates on this feature. In the context of this ticket a manual project means a project that is created without an ALM (ie: GitHub) connection, the automatic creation of a project through the Maven scanner would also be a manual project in this context.