diff --git a/pkg/controller/manager/manager_controller.go b/pkg/controller/manager/manager_controller.go
index b326b4e45c..802514a828 100644
--- a/pkg/controller/manager/manager_controller.go
+++ b/pkg/controller/manager/manager_controller.go
@@ -446,8 +446,16 @@ func (r *ReconcileManager) Reconcile(ctx context.Context, request reconcile.Requ
 		trustedSecretNames = append(trustedSecretNames, render.DexTLSSecretName)
 	}
 
+	// Voltron has to validate a public OIDC issuer for the Tigera OIDC type, so that configuration also
+	// needs the system root certificates in its trusted bundle. Either way this stays a bundle named
+	// for this component: the default-named tigera-ca-bundle belongs to the core controller, which
+	// renders it into the same namespace with a different set of certificates, and two controllers
+	// writing one ConfigMap with different contents overwrite each other on every reconcile.
+	includeSystemRoots := authenticationCR != nil && authenticationCR.Spec.OIDC != nil &&
+		authenticationCR.Spec.OIDC.Type == operatorv1.OIDCTypeTigera
+
 	bundleMaker, err := certificateManager.CreateNamedTrustedBundleFromSecrets(TrustedBundlePrefix, r.client,
-		helper.TruthNamespace(), false, trustedSecretNames...)
+		helper.TruthNamespace(), includeSystemRoots, trustedSecretNames...)
 	if err != nil {
 		r.status.SetDegraded(operatorv1.ResourceCreateError, "Error creating trusted bundle for manager", err, logc)
 	}
@@ -462,7 +470,6 @@ func (r *ReconcileManager) Reconcile(ctx context.Context, request reconcile.Requ
 			logc,
 			helper,
 			tenant,
-			authenticationCR,
 			certificateManager,
 			bundleMaker,
 			trustedSecretNames,
diff --git a/pkg/controller/manager/manager_controller_cloud.go b/pkg/controller/manager/manager_controller_cloud.go
index 5f0c56591b..39d1f177e6 100644
--- a/pkg/controller/manager/manager_controller_cloud.go
+++ b/pkg/controller/manager/manager_controller_cloud.go
@@ -70,22 +70,15 @@ func (r *ReconcileManager) handleCloudReconcile(
 	reqLogger logr.Logger,
 	helper utils.NamespaceHelper,
 	tenant *operatorv1.Tenant,
-	authenticationCR *operatorv1.Authentication,
 	certificateManager certificatemanager.CertificateManager,
 	bundleMaker certificatemanagement.TrustedBundle,
 	trustedSecretNames []string,
 	requestNamespace string,
 ) (certificatemanagement.TrustedBundle, render.ManagerCloudResources, *operatorv1.Tenant, *reconcile.Result, error) {
 
-	if authenticationCR != nil && authenticationCR.Spec.OIDC != nil && authenticationCR.Spec.OIDC.Type == operatorv1.OIDCTypeTigera {
-		var err error
-		bundleMaker, err = certificateManager.CreateTrustedBundleWithSystemRootCertificates()
-		if err != nil {
-			r.status.SetDegraded(operatorv1.ResourceCreateError, "failed to create trusted bundle with system root certs", err, reqLogger)
-			return nil, render.ManagerCloudResources{}, nil, nil, err
-		}
-	}
-
+	// The trusted bundle is built by the caller, which decides both its name and whether it carries the
+	// system root certificates. All that is left to do here is confirm the certificates it trusts are
+	// available before the manager is rendered.
 	for _, secret := range trustedSecretNames {
 		certificate, err := certificateManager.GetCertificate(r.client, secret, helper.TruthNamespace())
 		if err != nil {
@@ -97,10 +90,6 @@ func (r *ReconcileManager) handleCloudReconcile(
 			// stop reconciler iteration with no error as it is waiting for a resource to become available
 			return nil, render.ManagerCloudResources{}, nil, &reconcile.Result{}, nil
 		}
-
-		if bundleMaker != nil {
-			bundleMaker.AddCertificates(certificate)
-		}
 	}
 
 	mcr := render.ManagerCloudResources{
diff --git a/pkg/controller/manager/manager_controller_test.go b/pkg/controller/manager/manager_controller_test.go
index da3e7e77fa..46aed58b56 100644
--- a/pkg/controller/manager/manager_controller_test.go
+++ b/pkg/controller/manager/manager_controller_test.go
@@ -578,6 +578,34 @@ var _ = Describe("Manager controller tests", func() {
 				Expect(namespace.Labels["pod-security.kubernetes.io/enforce-version"]).To(Equal("latest"))
 			})
 
+			It("should leave the manager's trusted bundle alone on the cloud path", func() {
+				// The default-named tigera-ca-bundle belongs to the core controller, which renders it
+				// into the same namespace with a different set of certificates. If the manager writes
+				// that same ConfigMap the two controllers overwrite each other on every reconcile,
+				// which rolls every workload that mounts or inherits the bundle. The cloud path must
+				// therefore hand back the component-named bundle it was given, not substitute its own.
+				helper := utils.NewNamespaceHelper(false, render.ManagerNamespace, "")
+
+				// handleCloudReconcile resolves the tenant from this ConfigMap.
+				Expect(c.Create(ctx, &corev1.ConfigMap{
+					ObjectMeta: metav1.ObjectMeta{Name: utils.CloudAuthConfig, Namespace: common.OperatorNamespace()},
+					Data:       map[string]string{"tenantID": "Auth0ID"},
+				})).NotTo(HaveOccurred())
+
+				in, err := certificateManager.CreateNamedTrustedBundleFromSecrets(TrustedBundlePrefix, c, helper.TruthNamespace(), true)
+				Expect(err).NotTo(HaveOccurred())
+
+				out, _, _, res, err := r.handleCloudReconcile(ctx, log, helper, nil, certificateManager, in, nil, "")
+				Expect(err).NotTo(HaveOccurred())
+				Expect(res).To(BeNil())
+
+				Expect(out).NotTo(BeNil())
+				Expect(out.ConfigMap(helper.InstallNamespace()).Name).
+					To(Equal(certificatemanagement.TrustedBundleName(render.ManagerName, true)))
+				Expect(out.ConfigMap(helper.InstallNamespace()).Name).
+					NotTo(Equal(certificatemanagement.TrustedCertConfigMapName))
+			})
+
 			Context("image reconciliation", func() {
 				It("should use builtin images", func() {
 					mockStatus.On("RemoveCertificateSigningRequests", mock.Anything).Return()