Issue
Recently I discovered that the website has traffic from gtm-msr.appspot.com, as shown in the “Page title and screen class” report:
Analyze
This GTM is not mine.
It will load multiple GTMs and send data to multiple different GA4s, which is obviously machine traffic.
Its principle is that when you open the URL, your GTM will be loaded, and then GA4‘s page tracking will be triggered. What is tracked in GA4 is https://gtm-msr.appspot.com/render2?id=GTM-* **, this URL is obviously not your own domain name, so you can add a restriction to the GTM page tracking trigger.
Solution
Add a restriction to GTM’s page tracking trigger. The domain that the page is viewed will only be triggered if it is your own:
In this way, even if gtm-msr.appspot.com loads your GTM, it will not be triggered and send spam data to your GA4.