SonarQube version: Developer Edition Version 8.1 (build 31237)
In previous versions, code coverage was ignored in the quality gate if the number of new lines was below 20. (Not sure when exactly this was introduced, but it was working at least in 7.8, see SONAR-12121 issue.)
With the current version 8.1, branches with zero coverage and few code lines fail the quality gate again, meaning that the previously introduced feature is not working anymore.
We use the standard settings for coverage (i.e. Coverage > 80% on new code) in our quality gate.
Just to clarify, I don’t think the issue reported by me is the same that @derTobsch is seeing, as we are using a C#/MsBuild/OpenCover build environment.