GA4 adding _gl parameter when cross-domain tracking is not set up

Question

I have UA and GA4 set up on a site for some time now.

Suddenly a couple of weeks ago, in-page anchor links started to have parameters like the below added to them, causing the page to reload on click.

The parameters look like this:

_gl=1*1sgncz4*_up*MQ..*_ga*NTU1ODYzNjQxLjE2ODM3Mjk0MTI.*_ga_BC9YG14JH3*MTY4Mz 
 cyODM5MS4zLjEuMTY4MzcyOTQxOC4wLjAuMA..

I'm aware this could be for cross-domain tracking, but have nothing set up in GTM or GA4 for cross domain, and have also turned off all enhanced mesaurement / in-page link events but still had no luck finding what causes this.

Answer 1

It can happen if ad_storage and analytics_storage cookie consents are set to denied. It allow passing ID parameters through URL without storing them in cookies.

You can debug it using Tag Assistant or, if you're advanced user, looking for gcs parameter in requests sent to GA4. gcs reflects consent status, for example, gcs=G111 means all consents are granted.

Hope it will help.