R12.2 DMZ url not working

The workaround is to the ensure that the following configuration updates are made:
Customize the Oracle E-Business Suite applications context file on each node to remove the cluster definition for nodes that are not required to be in the cluster.
For example see s_oacore_nodes, s_forms_nodes,s_oafm_nodes,s_forms-c4ws_nodes
Customize the Oracle HTTP Server configuration files like mod_wl_ohs.conf, apps.conf present in the webtier instance home to remove the nodes
that are not participating in the cluster configuration.
Set DynamicServerList to OFF in mod_wl_ohs.conf . The 12.2.3 configuration is shipped  with this setting.
An example is given below to illustrate the change required in applications context file and config files.
The example only mention about the oacore managed server setup. Similar changes must be done for all the managed servers.
Perform the required changes on the run edition of the file E-Business Suite file system.
The changes will be carried over automatically to the patch edition of the file system during an online patching cycle.
Internal application tier nodes: finance.example.net, procurement.example.net
Internal web entry point : employees.example.net
External application tier nodes : sourcing.example.com, supplier.example.com
External web entry point: partners.example.com
The default configuration laid down by Rapid Install/Rapid Clone will include all nodes in the cluster configuration as shown below . This configuration is not desirable as the application tier nodes in the configuration belong to two different entry points.
Applications context file
<oacore_nodes oa_var="s_oacore_nodes">finance.example.net:7203,procurement.example.net:7203,sourcing.example.com:7203,supplier.example.com:7203</oacore_nodes>
mod_wl_ohs.conf
WebLogicCluster finance.example.net:7203,procurement.example.net:7203,supplier.example.com.com:7203,sourcing.example.com:7203
apps.conf
BalancerMember http://finance.example.net:7203/OA_HTML/classes
BalancerMember http://procurement.example.net:7203/OA_HTML/classes
BalancerMember http://supplier.example.com:7203/OA_HTML/classes
BalancerMember http://sourcing.example.com:7203/OA_HTML/classes
You need to make manual updates to the application context files on all nodes and the configuration files ( mod_wl_ohs.conf/apps.conf) to remove the unwanted nodes from the cluster configuration. For example on nodes finance/procurement, the adjusted configuration will be as shown below:
Applications context file
<oacore_nodes oa_var="s_oacore_nodes">finance.example.net:7203,procurement.example.net:7203</oacore_nodes>
mod_wl_ohs.conf
WebLogicCluster finance.example.net:7203,procurement.example.net:7203
apps.conf
BalancerMember http://finance.example.net:7203/OA_HTML/classes
BalancerMember http://procurement.example.net:7203/OA_HTML/classes
On the supplier/sourcing nodes , the adjusted configuration will be as shown below:
Applications context file
<oacore_nodes oa_var="s_oacore_nodes">sourcing.example.com:7203,supplier.example.com:7203</oacore_nodes>
mod_wl_ohs.conf
WebLogicCluster supplier.example.com.com:7203,sourcing.example.com:7203
apps.conf
BalancerMember http://supplier.example.com:7203/OA_HTML/classes
BalancerMember http://sourcing.example.com:7203/OA_HTML/classes