In Google Analytics 4 report, you can see (not set), but the reason for it is different. (not set) is a placeholder name that Google Analytics uses when it hasn’t received information for a dimension.
Landing Page
Normally, the user opens the landing page, and the page_view event is sent.
But if the user opens the landing page, other events are sent faster than the page_view event tracking, and the page_view is not sent, the user closes or leaves, which will cause not set.
Session Source/Medium
So far I know of two reasons:
- When the session is opened, there will be a session_start, there will be page_location and page_referral on it, and Source/Medium will get the value from these parameters, but the actual situation is that some sessions will have multiple or zero session_starts, these abnormal session_starts If there is no accurate page_location and page_referral, it will cause Source/Medium to be not set.
- If you send data through the measurement protocol without a session_id parameter, it will be classified as not set.
Geographic Location
“City” and “Country” are displayed as “(not set)”
Google Analytics uses a third-party datasource to determine your visitors’ geographical locations. If our third-party vendor does not have an accurate record of the visitor location, Google Analytics displays a (not set) entry.
Transaction ID
If you deploy GA4’s e-commerce tracking, and the transaction IDs are all numbers, then you may encounter the transaction Id is not set. This GA4 bug was discovered by Simo ahava in 2020.
This bug does not seem to be fixed yet, it is recommended to use a combination of English letters and numbers for the transaction ID.
For more bugs about GA4, it is recommended to see:Some Bugs in Google Analytics 4
