Why Is Google Consent Mode v2 Not Working?

A cookie banner can appear on the page while Consent Mode is still broken. The useful question is not only whether visitors can click a button, but whether Google receives the right default and update signals at the right time.

Start with the three moving parts

A working Consent Mode setup needs a default consent state before normal tags run, an update after the visitor makes a choice, and Google tags that read those states. If one part is missing, the setup can look correct from the outside and still fail in GTM or Tag Assistant.

Check the default state first

Open a fresh browser session with no stored consent. Before you click the banner, the default state should already exist. For many European setups, optional analytics and advertising storage should not start as granted before the visitor has made a choice.

Use an incognito window or clear the site consent cookie
Open GTM Preview before loading the page
Check the earliest events before clicking the banner

Then test the update after choice

Click reject all, accept all, and a custom preference choice if your banner supports it. Each choice should send a clear update to Google Consent Mode. If the banner changes visually but GTM does not receive an update, the bridge between the banner and tags is the part to fix.

Look for tags outside the consent flow

A common problem is that GA4, Google Ads, or another script is loaded directly on the page outside GTM or before your CMP has initialized. In that case Consent Mode may be configured in GTM, but the website still writes cookies or sends requests too early.

Check the page source for hardcoded Google tags
Review third-party apps and plugins
Look at browser cookies after reject all

Use a repeatable fix path

The practical fix is to run the CMP early, set defaults before normal tags, make the banner send updates, and verify the result after accept and reject tests. CleanCMP keeps the banner, scanner, GTM install path, signal mapping, reporting, and proof records in one workspace so the setup is easier to test.

FAQs

Can Consent Mode be broken even if the banner appears?

Yes. The banner is only the visitor interface. Consent Mode also needs default and update signals that Google tags can read.

What is the first thing to check?

Start with a fresh visitor and check whether a default consent state exists before normal analytics and advertising tags run.

Can CleanCMP help with this?

CleanCMP gives you a GTM install path, Consent Mode mapping, scanner evidence, and proof records so you can test the setup instead of guessing.

Set it up in CleanCMP

CleanCMP gives you the banner builder, cookie scanner, GTM install path, Consent Mode v2 signal mapping, proof records, and reporting in one focused workspace.

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