Thanks for the update @webkocken. I noticed some plugins that can be used to insert custom snippets, including Analytics snippets. These include My Custom Code and Code Snippets. There is also a child theme related plugin and Rank Math, but of which may have Analytics configurations. Did you check these for the existence of any such snippets?
Note also we are limited to Site Kit support queries here in the plugin forums. While the GA4 snippet that’s on your site is not placed via Site Kit you can use the Health Check & Troubleshooting plugin to determine the cause. If you are unable to locate the snippet from checking the mentioned plugins above, you can follow the below steps:
You can try the below steps if you wish, which may help find the plugin or theme where the snippet was inserted:
- Login to your site from a Chrome browser incognito window
- Install and activate the Health Check & Troubleshooting plugin.
- Navigate to “Plugins > Health Check & Troubleshooting > Troubleshoot“. (This will temporarily deactivate other plugins and switch to a default theme – for you only, as a logged in user).
- Check your sites source code, I suspect you won’t find a snippet placed
- From back in your Health Check plugin click on the “Available Plugins” tab at the top right and then click on the “Enable” option next to any additional plugins, before then visiting your sites source code once more.
- Enable your plugins one by one while rechecking your sites source code each time until you locate the snippet. You’ll need to refresh/reload the source code page each time.
- If you can’t locate the existing Analytics snippet try activating your present theme from within troubleshooting mode before checking the source code once mode (Please refresh the page before checking).
Once you locate the source of the additional Analytics snippet you can exit troubleshooting mode afterwards.
Hopefully the above is of use.