Due to a bug (in our backlog), you have to make sure that a couple internal analysis parameters are completed if you’re operating outside of Azure Pipelines and the Azure DevOps Extension. This shouldn’t be neccssary as SonarCloud should use the binding data.
You can find more details here:
I guess those build variables won’t be available to you in Harness, but if you can populate that same data you should be able to get PR decoration working.