diff --git a/mmv1/products/certificatemanager/terraform.yaml b/mmv1/products/certificatemanager/terraform.yaml
index a841eb81070b..820ca8a5d9b9 100644
--- a/mmv1/products/certificatemanager/terraform.yaml
+++ b/mmv1/products/certificatemanager/terraform.yaml
@@ -38,19 +38,12 @@ overrides: !ruby/object:Overrides::ResourceOverrides
           dns_auth_name2: "dns-auth2"
           dns_auth_subdomain2: "subdomain2"
           cert_name: "dns-cert"
-        ignore_read_extra:
-          - "managed.0.dns_authorizations"
-    examples:
       - !ruby/object:Provider::Terraform::Examples
         name: "certificate_manager_self_managed_certificate"
         primary_resource_id: "default"
         vars:
           cert_name: "self-managed-cert"
     properties:
-      managed.dnsAuthorizations: !ruby/object:Overrides::Terraform::PropertyOverride
-        # We don't support ignore_read on nested fields
-        ignore_read: true
-        custom_flatten: "templates/terraform/custom_flatten/certificate_manager_certificate_managed_dns_auth.go.erb"
       selfManaged.certificatePem: !ruby/object:Overrides::Terraform::PropertyOverride
         sensitive: true
       selfManaged.privateKeyPem: !ruby/object:Overrides::Terraform::PropertyOverride
@@ -61,6 +54,8 @@ overrides: !ruby/object:Overrides::ResourceOverrides
         ignore_read: true
       scope: !ruby/object:Overrides::Terraform::PropertyOverride
         diff_suppress_func: 'certManagerDefaultScopeDiffSuppress'
+      managed.dnsAuthorizations: !ruby/object:Overrides::Terraform::PropertyOverride
+        diff_suppress_func: 'projectNumberDiffSuppress'
     custom_code: !ruby/object:Provider::Terraform::CustomCode
       constants: templates/terraform/constants/cert_manager.erb
   CertificateMap: !ruby/object:Overrides::Terraform::ResourceOverride
diff --git a/mmv1/templates/terraform/custom_flatten/certificate_manager_certificate_managed_dns_auth.go.erb b/mmv1/templates/terraform/custom_flatten/certificate_manager_certificate_managed_dns_auth.go.erb
deleted file mode 100644
index 9ef7931f054b..000000000000
--- a/mmv1/templates/terraform/custom_flatten/certificate_manager_certificate_managed_dns_auth.go.erb
+++ /dev/null
@@ -1,17 +0,0 @@
-<%# The license inside this block applies to this file.
-	# Copyright 2021 Google Inc.
-	# Licensed under the Apache License, Version 2.0 (the "License");
-	# you may not use this file except in compliance with the License.
-	# You may obtain a copy of the License at
-	#
-	#     http://www.apache.org/licenses/LICENSE-2.0
-	#
-	# Unless required by applicable law or agreed to in writing, software
-	# distributed under the License is distributed on an "AS IS" BASIS,
-	# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-	# See the License for the specific language governing permissions and
-	# limitations under the License.
--%>
-func flatten<%= prefix -%><%= titlelize_property(property) -%>(v interface{}, d *schema.ResourceData, config *Config) interface{} {
-	return d.Get("managed.0.dns_authorizations")
-}