diff --git a/x-pack/plugins/fleet/server/services/agent_policy.ts b/x-pack/plugins/fleet/server/services/agent_policy.ts
index 35b963560d6ea..15531d4a4eb4c 100644
--- a/x-pack/plugins/fleet/server/services/agent_policy.ts
+++ b/x-pack/plugins/fleet/server/services/agent_policy.ts
@@ -486,7 +486,7 @@ class AgentPolicyService {
     agentPolicyId: string
   ) {
     const esClient = appContextService.getInternalUserESClient();
-    if (appContextService.getConfig()?.agents.fleetServerEnabled) {
+    if (appContextService.getConfig()?.agents?.fleetServerEnabled) {
       await this.createFleetPolicyChangeFleetServer(soClient, esClient, agentPolicyId);
     }
 
diff --git a/x-pack/plugins/fleet/server/services/agents/acks.test.ts b/x-pack/plugins/fleet/server/services/agents/acks.test.ts
index 1626df4fd02ca..650480ee630a6 100644
--- a/x-pack/plugins/fleet/server/services/agents/acks.test.ts
+++ b/x-pack/plugins/fleet/server/services/agents/acks.test.ts
@@ -104,19 +104,19 @@ describe('test agent acks services', () => {
         } as AgentEvent,
       ]
     );
-    expect(mockSavedObjectsClient.bulkUpdate).toBeCalled();
-    expect(mockSavedObjectsClient.bulkUpdate.mock.calls[0][0]).toHaveLength(1);
-    expect(mockSavedObjectsClient.bulkUpdate.mock.calls[0][0][0]).toMatchInlineSnapshot(`
-      Object {
-        "attributes": Object {
+    expect(mockSavedObjectsClient.bulkUpdate).not.toBeCalled();
+    expect(mockSavedObjectsClient.update).toBeCalled();
+    expect(mockSavedObjectsClient.update.mock.calls[0]).toMatchInlineSnapshot(`
+      Array [
+        "fleet-agents",
+        "id",
+        Object {
           "packages": Array [
             "system",
           ],
           "policy_revision": 4,
         },
-        "id": "id",
-        "type": "fleet-agents",
-      }
+      ]
     `);
   });
 
@@ -166,19 +166,19 @@ describe('test agent acks services', () => {
         } as AgentEvent,
       ]
     );
-    expect(mockSavedObjectsClient.bulkUpdate).toBeCalled();
-    expect(mockSavedObjectsClient.bulkUpdate.mock.calls[0][0]).toHaveLength(1);
-    expect(mockSavedObjectsClient.bulkUpdate.mock.calls[0][0][0]).toMatchInlineSnapshot(`
-      Object {
-        "attributes": Object {
+    expect(mockSavedObjectsClient.bulkUpdate).not.toBeCalled();
+    expect(mockSavedObjectsClient.update).toBeCalled();
+    expect(mockSavedObjectsClient.update.mock.calls[0]).toMatchInlineSnapshot(`
+      Array [
+        "fleet-agents",
+        "id",
+        Object {
           "packages": Array [
             "system",
           ],
           "policy_revision": 4,
         },
-        "id": "id",
-        "type": "fleet-agents",
-      }
+      ]
     `);
   });
 
@@ -228,8 +228,8 @@ describe('test agent acks services', () => {
         } as AgentEvent,
       ]
     );
-    expect(mockSavedObjectsClient.bulkUpdate).toBeCalled();
-    expect(mockSavedObjectsClient.bulkUpdate.mock.calls[0][0]).toHaveLength(0);
+    expect(mockSavedObjectsClient.bulkUpdate).not.toBeCalled();
+    expect(mockSavedObjectsClient.update).not.toBeCalled();
   });
 
   it('should not update config field on the agent if a policy change for an old revision is acknowledged', async () => {
@@ -275,8 +275,8 @@ describe('test agent acks services', () => {
         } as AgentEvent,
       ]
     );
-    expect(mockSavedObjectsClient.bulkUpdate).toBeCalled();
-    expect(mockSavedObjectsClient.bulkUpdate.mock.calls[0][0]).toHaveLength(0);
+    expect(mockSavedObjectsClient.bulkUpdate).not.toBeCalled();
+    expect(mockSavedObjectsClient.update).not.toBeCalled();
   });
 
   it('should fail for actions that cannot be found on agent actions list', async () => {
diff --git a/x-pack/plugins/fleet/server/services/agents/actions.ts b/x-pack/plugins/fleet/server/services/agents/actions.ts
index 70524f7b34814..031fdc97cdfde 100644
--- a/x-pack/plugins/fleet/server/services/agents/actions.ts
+++ b/x-pack/plugins/fleet/server/services/agents/actions.ts
@@ -72,7 +72,7 @@ async function createAction(
   );
 
   if (
-    appContextService.getConfig()?.agents.fleetServerEnabled &&
+    appContextService.getConfig()?.agents?.fleetServerEnabled &&
     isAgentActionSavedObject(actionSO)
   ) {
     const body: FleetServerAgentAction = {
@@ -134,7 +134,7 @@ async function bulkCreateActions(
     }))
   );
 
-  if (appContextService.getConfig()?.agents.fleetServerEnabled) {
+  if (appContextService.getConfig()?.agents?.fleetServerEnabled) {
     await esClient.bulk({
       index: AGENT_ACTIONS_INDEX,
       body: actionSOs.flatMap((actionSO) => {
diff --git a/x-pack/plugins/fleet/server/services/agents/checkin/state_new_actions.ts b/x-pack/plugins/fleet/server/services/agents/checkin/state_new_actions.ts
index 4377e1ad3a285..6679167a692c4 100644
--- a/x-pack/plugins/fleet/server/services/agents/checkin/state_new_actions.ts
+++ b/x-pack/plugins/fleet/server/services/agents/checkin/state_new_actions.ts
@@ -110,7 +110,7 @@ async function getOrCreateAgentDefaultOutputAPIKey(
   esClient: ElasticsearchClient,
   agent: Agent
 ): Promise<string> {
-  if (appContextService.getConfig()?.agents.fleetServerEnabled) {
+  if (appContextService.getConfig()?.agents?.fleetServerEnabled) {
     if (agent.default_api_key) {
       return agent.default_api_key;
     }
diff --git a/x-pack/plugins/fleet/server/services/setup.ts b/x-pack/plugins/fleet/server/services/setup.ts
index 1cd1df7a66a56..bb988fd3c11c5 100644
--- a/x-pack/plugins/fleet/server/services/setup.ts
+++ b/x-pack/plugins/fleet/server/services/setup.ts
@@ -86,7 +86,7 @@ async function createSetupSideEffects(
   // packages that are stuck in the installing state.
   await ensurePackagesCompletedInstall(soClient, callCluster);
 
-  if (appContextService.getConfig()?.agents.fleetServerEnabled) {
+  if (appContextService.getConfig()?.agents?.fleetServerEnabled) {
     await ensureInstalledPackage({
       savedObjectsClient: soClient,
       pkgName: FleetServerPackage,