A support ticket is open for this, perhaps someone else has experienced this and can assist.
On the production system a UDT has an OPC tag pointing to device “PLC_NEW”.
When a new gateway backup is restored this UDT changes such that the OPC tag points to device “PLC_OLD”.
The UDT was modified a couple years ago.
The gateway backup was made on the production system but restored on a development system.
This issue was discovered during a test of gateway redundancy, the UDT also reverted to the old definition sometime during either the fail over to the backup node or back to the primary node.