GA4 has introduced a warning system for (not set) values, indicated by an exclamation icon. The tooltip states that changes may take 24 to 48 hours to reflect in reports and that the report contains a (not set) value due to a lack of received data. It suggests that users learn how to resolve (not set) data to improve attribution data for acquisition channels. However, this warning may create more confusion and false expectations rather than providing clarity.
A primary cause of (not set) in attribution is attributed to the tool itself, indicating a need for fixes before issuing warnings. The ongoing issues with sessions in GA4 highlight that (not set) is yet another symptom of a larger problem, leaving users awaiting a genuine solution.
