As stated by my colleague, this issue was resolved in the latest version of the Facebook for WooCommerce extension (2.6.10). If you’re still experiencing the issue, please ensure you update to the latest version and try the connection again.
If the issue persists on the latest version, then it’s likely caused by a conflict on your site and the next step would be to try the connection with just WooCommerce and the Facebook for WooCommerce extension installed.
Here’s how to go about that:
1. Install and activate the Health Check plugin – Changes made in the plugin’s troubleshooting mode will only apply to your session.
2. Enable the plugin’s troubleshooting mode and activate a default theme such as Twenty Twenty. See: Troubleshooting using Health Check
3. Activate just WooCommerce and the Facebook for WooCommerce extension (In troubleshooting mode)
4. Try to set up the Facebook for WooCommerce extension – See: Getting started guide
That should allow you to complete the setup without any interference by a script on your site. Once the setup is complete, you can deactivate the troubleshooting mode as well as the health check plugin.
If that doesn’t help, let us know so we can help further.
I hope this helps!