Answer:
It’s actually pretty typical to see page_view firing before session_start in GA4 Debug View. The session_start event doesn’t fire independently - it gets sent with other events using the _ss parameter. So unless you see it fire way later in the session, there’s nothing to stress about. Now, if session_start doesn’t fire at all, that indicates the _ss parameter didn’t get picked up. Keep in mind, too, that it can double fire if you open several tabs in quick succession. While it’s fine for casual debugging, I wouldn’t use it for super accurate data in large reports.
Why does page_view fire before session_start in GA4 Debug View, and is it an issue if session_start doesn't fire at all?
In GA4, it's normal for page_view to fire before session_start in Debug View.
