#98420 verifies that the election scheduler is not running when a cluster is stable, but this assertion does not hold in the `AtomicRegisterCoordinatorTests` suite. This issue tracks the work to investigate and fix up the problem.
test/framework/src/main/java/org/elasticsearch/cluster/coordination/AbstractCoordinatorTestCase.java
? nodeSettings
                    : Settings.builder()
                        .put(nodeSettings)
                        .putList(
                            ClusterBootstrapService.INITIAL_MASTER_NODES_SETTING.getKey(),
                            ClusterBootstrapService.INITIAL_MASTER_NODES_SETTING.get(Settings.EMPTY)
                        )
                        .build(); 
                transportService = mockTransport.createTransportService(
                    settings,
                    threadPool,
                    getTransportInterceptor(localNode, threadPool),
                    a -> localNode,
                    null,
                    emptySet()
                );
                masterService = new AckedFakeThreadPoolMasterService(
                    localNode.getId(),
                    threadPool,
                    runnable -> deterministicTaskQueue.scheduleNow(onNode(runnable))
                );
                final ClusterSettings clusterSettings = new ClusterSettings(settings, ClusterSettings.BUILT_IN_CLUSTER_SETTINGS);
                clusterApplierService = new DisruptableClusterApplierService(
                    localNode.getId(),
                    localNode.getEphemeralId(),
                    settings,
                    clusterSettings,
                    deterministicTaskQueue,
                    this::onNode,
                    threadPool