Issue with Google Tag Manager Consent Mode integration – Consent remains denied

[ItM71]

Hy everyone,

first of all, thank you for the amazing work on this library — it's incredibly helpful and flexible.

We are currently trying to integrate CookieConsent with Google Tag Manager (GTM) and Consent Mode (v2), following the opt-in approach. Our goal is to load GTM only after the user has accepted the analytics category, and to properly update consent settings before any tags fire.

Here’s the general setup:

• mode: 'opt-in'
• onConsent and onAccept callbacks are used to dynamically load GTM
• Consent update is pushed using gtag('consent', 'update', { ... })
• GTM loads correctly after acceptance, and tags do fire
• However, consent remains "denied" in the Consent Mode debugger, and no collect request is sent to GA4

✅ What we are doing in onAccept:

onAccept: function () {
  if (CookieConsent.acceptedCategory('analytics')) {
    window.dataLayer = window.dataLayer || [];
    function gtag(){ dataLayer.push(arguments); }

    gtag('consent', 'default', {
      ad_storage: 'granted',
      analytics_storage: 'granted'
    });

    dataLayer.push({ event: 'cookie_consent_granted' });

    loadGTM('GTM-XXXXXXX'); // dynamically appends GTM script
  }
}
We also tried with 'update' instead of 'default', and tested various delays.

Even though GTM loads dynamically after the gtag consent update, Consent Mode continues to report denied values for both ad_storage and analytics_storage.

If we go back to loading GTM statically (without dynamic injection), and let GTM handle consent, everything works fine and collect hits are visible.

❓ Main questions:

Is this dynamic integration pattern still valid?
Should we delay GTM script loading further?
Is there something missing in how GTM expects consent signals when initialized dynamically?

Any help or shared experience would be greatly appreciated 🙏

Thanks in advance!