#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
private final CoordinatorStrategy coordinatorStrategy;
        @Nullable 
        private List<TransportAddress> seedHostsList;
        Cluster(int initialNodeCount) {
            this(initialNodeCount, true, Settings.EMPTY);
        }
        public Cluster(int initialNodeCount, boolean allNodesMasterEligible, Settings nodeSettings) {
            this(initialNodeCount, allNodesMasterEligible, nodeSettings, () -> new StatusInfo(HEALTHY, "healthy-info"));
        }
        Cluster(int initialNodeCount, boolean allNodesMasterEligible, Settings nodeSettings, NodeHealthService nodeHealthService) {
            this.nodeHealthService = nodeHealthService;
            this.countingPageCacheRecycler = new CountingPageCacheRecycler();
            this.recycler = new BytesRefRecycler(countingPageCacheRecycler);
            deterministicTaskQueue.setExecutionDelayVariabilityMillis(DEFAULT_DELAY_VARIABILITY);
            this.coordinatorStrategy = createCoordinatorStrategy();
            assertThat(initialNodeCount, greaterThan(0));
            final Set<String> masterEligibleNodeIds = Sets.newHashSetWithExpectedSize(initialNodeCount);
            clusterNodes = new ArrayList<>(initialNodeCount);
            for (int i = 0; i < initialNodeCount; i++) {
                final ClusterNode clusterNode = new ClusterNode(
                    nextNodeIndex.getAndIncrement(),
                    allNodesMasterEligible || i == 0 || randomBoolean(),
                    nodeSettings,
                    nodeHealthService
                );
                clusterNodes.add(clusterNode);
                if (clusterNode.getLocalNode().isMasterNode()) {
                    masterEligibleNodeIds.add(clusterNode.getId());
                }
            }