Catching up on unattended community posts. Sorry for the very long delay. Your post caught my attention.
I don’t know by what magic you got your PR decorated with SonarQube 6.7.4, since this is a feature that was added in SonarQube 7.9 (released in June 2019).
That must be by using some 3rd party plugins maybe ? (In that case there’s nothing we can do for you at SonarSource, you should ask the plugin maintainer).
Anyhow: SonarQube 7.9 and higher support Azure DevOps (VSTS) PR decoration, starting from Developer Edition (ie all Editions except the Community Edition).
And when PRs are decorated you definitely have the issue type. Check out the below screenshot: