Warnings Next Generation 9.11.1
In the documentation of the Warnings Next Generation plugin, under the publishIssues and recordIssues, the description of thresholds on qualityGates states "The threshold defines the minimum number of warnings that will fail a build. Values less or equal zero are ignored. So if you want to fail a build that has one warning, set this field to 1."
Setting the threshold values less or equal to zero does NOT cause the quality gate to be ignored. All quality gates fail since even a value of zero succeeds the greater than or equal test.
For now I have worked around this by setting the thresholds to 10,000 instead of 0. But it would be better if a the quality gates were ignored instead of comparing to a 10,000 threshold.