Increase in Unassigned (not set) traffic in Google Analytics after Server Side implementation

Do you have an increase in Unassigned (not set) traffic in Google Analytics? In this support guide, we're exploring potential causes and solutions.

In Google Tag Manager, set the web container trigger to initialization instead of all pages. This ensures the ‘all pages’ trigger is called before the events, avoiding concurrent triggers which can lead to issues like the Unassigned GA4 Traffic.

Note: this solution only works if you have configured Consent Mode V2. For Google tags with automatic consent management, adjust the Additional Consent Checks setting to 'no additional consent required' instead of 'not set'. By doing this, you specifically indicate which tags do not require an extra consent setting. This reduces the amount of unassigned traffic (not set) data within Google Tag Manager.

This only applies to tags where consent is managed automatically! For tags where this is not the case, for example, with Facebook, you should leave the additional consent unchanged.

In the server container, you can update the Cookies and Client Identification System as an alternative solution to address unassigned traffic in GA4. To do this, navigate to 'Clients' -> 'GA4', and click on 'More Settings'. Locate the 'Cookies and Client Identification' section and change the setting from 'Server Managed' to 'JavaScript Managed'.

This change modifies how attribution is measured and often resolves the issue of unassigned traffic. While it is not guaranteed to work in all cases, it is a highly effective solution in most scenarios.

These are the key reasons for increase in Unassigned (not set) traffic in Google Analytics. I your issue isn't listed here or if you've discovered another cause relevant to other users, send us a support ticket.