error with oci cli on Windows

I have installed the Oracle OCI CLI on my Windows machine with the MSI installer.
I am able to execute oci cli commands from the command prompt

UNLESS I am connected to my corporate VPN via the CATO client.

In this case I get the following error:

C:\Users\kkline>oci os ns get
SSLException:
{
"client_version": "Oracle-PythonCLI/3.72.0",
"logging_tips": "Please run the OCI CLI command using --debug flag to find more debug information.",
"message": "It looks like you are missing some additional certificates for operation. run 'curl request_endpoint' to make sure you are able to call endpoint using curl.",
"request_endpoint": " GET https://objectstorage.uk-london-1.oraclecloud.com",
"target_service": "CLI",
"timestamp": "2026-01-22T04:00:04.684205",
"troubleshooting_tips": "If you have a root certificate, either use --cert-bundle <path_to_cert_bundle_file> with CLI command or set REQUESTS_CA_BUNDLE env variable. i.e export REQUESTS_CA_BUNDLE=path_to_cert_bundle_file on POSIX-compliant bash-like shell terminal. See [https://docs.oracle.com/iaas/Content/API/SDKDocs/clitroubleshooting.htm] for more information about resolving this error. If you are unable to resolve this issue, run this CLI command with --debug option and contact Oracle support and provide them the full error message."
}

I have tried

set OCI_CLI_SKIP_VERIFY_SSL=True

and

set REQUESTS_CA_BUNDLE="C:\Program Files (x86)\Oracle\oci_cli\Lib\certifi"

Neither solves the problem.

Any help or guidance would be greatly appreciated!

Thanks

Ken

Start by reproducing oci os ns get on Windows with and without the CATO VPN, then run it with --debug and test the listed request endpoint with curl. Compare the behavior of OCI_CLI_SKIP_VERIFY_SSL and REQUESTS_CA_BUNDLE using the paths shown in the report. Done means identifying whether the failure is in the CLI or the VPN certificate chain and documenting a verified resolution.