poweroffcommands, the IP address of imported GCP VM instances might not appear in Address Manager. For more information, refer to Known issues.
If the VM Instance in GCP has associated subnets, that information is also included in the virtual machine device data. The following example illustrates the associated subnets of a virtual machine as they appear in Address Manager.
In the IP Space tab, you can navigate to the network level and find IP addresses that have been assigned to virtual machines based on their associated IP address configured in GCP. The following image displays an IPv4 network with IP addresses associated to virtual machines.