「GA4 Bug」New Users Data Missing in GA4

Update time: June 24, 2025

Issue

Beginning in mid-May 2024, some GA4 New Users data was severely lost, with a drop of more than 90%, such as:

Reason

Reason 1

Some GA4, without any adjustments, started to have data in June, such as:

But some GA4 still have no data, which is probably a bug.

Reason 2

Please check whether the Effective User ID is garbled in User Explorer:

If so, this is due to enabling User-provided data collection. and the wrong Users ID is automatically obtained due to the code structure of the page.

Read More：「GA Bug」Effective User ID in the Exploration Eeport is Garbled

Solution

If the Effective User ID is garbled, please turn off the User-provided data collection.

Others, waiting for official fix.