I removed a custom field but it still shows on the backend

I have only three custom fields setup using your plugin.

For some reason, one I deleted always stays and is always in the back-end of every product.

I can’t change it nor delete it because it doesn’t exist under “Custom Fields” then field groups, yet it shows up for my product.

I have deactivated and deleted the plugin and re-installed, yet when I do so the issue is still there.

maybe if I can find where the actual custom fields are stored I can delete it that way.

https://wordpress.org/plugins/advanced-custom-fields/