Configuring a remote for google drive finishes successfully, but no client secret is copied. The client secret stays empty. No file like "oauth-project-.json" is copied or created. Nor used. This seems a problem with modern browsers. I've tried Vivaldi, Chrome, Firefox. Got all times the same: no access. Google Drive is shown empty. No files found.
With an other, older config (configured to access Google Drive config only) it works. But the config is different here:
There is of course some chance that you discovered a new bug but otherwise google drive configuration works without any issues with all latest browsers I use.
If you post step by step what you are doing it can help to diagnose the issue. It is impossible to guess details from your description.
If you are using a service account, they have their own client ID/secret so if you are using a service account, you should leave both fields blank anyway.
Yes, this was the solution. You can use the cient_id and client_secret OR service_account_file, but not both. Even having the client_id and service_account_file defined does not good with 1.64.0, while it works with 1.63.1.