The issue you’re encountering with Wordfence blocking the addition of Google Tag Manager (GTM) code via the Code Snippets plugin is not related to Code Snippets plugin itself but is due to Wordfence’s security settings. To resolve this, you can set Wordfence to Learning Mode, which allows it to recognize and permit legitimate actions:

1. Navigate to the Wordfence Dashboard and click on ‘Manage WAF’.
2. Under ‘Basic Firewall Options’, set the Web Application Firewall Status to ‘Learning Mode’.
3. Add your GTM code using the Code Snippets plugin.
4. After completing the action, revert the Web Application Firewall Status back to ‘Enabled and Protecting’.

This process helps Wordfence learn that the action is safe and should be allowed in the future. For more detailed instructions, refer to Wordfence’s guide on Learning Mode.

If you continue to experience issues, consider reaching out to Wordfence support for further assistance.

Thank you,
Pau.