#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
);
                clusterService = new ClusterService(settings, clusterSettings, masterService, clusterApplierService);
                masterHistoryService = new MasterHistoryService(transportService, threadPool, clusterService);
                clusterService.setNodeConnectionsService(
                    new NodeConnectionsService(clusterService.getSettings(), threadPool, transportService)
                );
                final Collection<BiConsumer<DiscoveryNode, ClusterState>> onJoinValidators = Collections.singletonList(
                    (dn, cs) -> extraJoinValidators.forEach(validator -> validator.accept(dn, cs))
                );
                final AllocationService allocationService = ESAllocationTestCase.createAllocationService(Settings.EMPTY);
                final NodeClient client = new NodeClient(Settings.EMPTY, threadPool);
                final var coordinationServices = coordinatorStrategy.getCoordinationServices(
                    threadPool,
                    settings,
                    clusterSettings,
                    persistedState,
                    new NodeDisruptibleRegisterConnection()
                );
                coordinator = new Coordinator(
                    "test_node",
                    settings,
                    clusterSettings,
                    transportService,
                    client,
                    getNamedWriteableRegistry(),
                    allocationService,
                    masterService,
                    this::getPersistedState,
                    Cluster.this::provideSeedHosts,
                    clusterApplierService,