Maven SettingsProvider and GlobalSettingsProvider are designed for 'classic' Jenkins jobs relying on "AbstractBuild" and are NOT compatible with pipeline jobs that rely on "WorkflowRun" and "Run" (see jenkins.mvn.SettingsProvider#supplySettings(AbstractBuild<?, ?> build, TaskListener listener))".

Maven SettingsProvider and GlobalSettingsProvider should be able to supply Maven settings.xml and global settings.xml to "Run".