The vSwitch configured for your function is in a zone that Function Compute does not support. To fix this, create a new vSwitch in a supported zone and update your function's Virtual Private Cloud (VPC) configuration.
Resolve the error
Identify a supported zone. View the zones that are supported by Function Compute and note down one of these zones.
Create a vSwitch in a supported zone. In the VPC console, create a vSwitch and select the zone you identified in step 1. For step-by-step instructions, see Create and manage a VPC.
If Function Compute cannot be found in the vSwitch after creation, the vSwitch was not successfully created. In this case, create a new vSwitch in a supported zone and try again.
Update your function's VPC configuration. In the Function Compute console, go to your function's VPC settings and replace the existing vSwitch ID with the ID of the vSwitch you created in step 2.
Verify the fix
Invoke your function. If it runs without the vSwitch is in unsupported zone error, the configuration is correct and the function can access VPC resources.
vSwitches in different zones within the same VPC can communicate with each other over an internal network by default. Creating a vSwitch in a different zone does not break connectivity between existing VPC resources.