Solution:
The firewall rule allowing ingress traffic on tcp port 80 from IP ranges: 0.0.0.0/0 is the right choice for your setup, so the firewall rules might not be the cause of the issue.
I would suggest you to check the following options for troubleshooting –
- Make sure your plugins are all updated. You can stop/remove the plugins which are not in use and download the file with trusted and updated plugins.
- Ensure that your hypertext access (.htaccess) file is not broken.
- Check the ‘error.log’ file to find any specific error.
Please refer to following link for details on how to connect to your wordpress site in GCP via FTP – https://onepagezen.com/manage-wordpress-files-on-google-cloud-platform
You can also explore other ways to successfully download your wordpress files in the following link – https://blogvault.net/how-to-migrate-wordpress-site