There’s currently a UI bug in Google Tag Manager (GTM) Preview Mode affecting Consent Mode visibility.
When Consent Mode is implemented through GTM templates using GTM’s Consent Mode APIs (setDefaultConsentState, updateConsentState), the Preview Mode fails to display consent interactions or populate the Consent tab correctly.
👉 Important: Consent Mode itself still works properly only the Preview/Tag Assistant interface is glitching, making verification difficult.
The issue has been reported to Google. Direct gtag(‘consent’…) implementations still appear normally in Preview Mode.
Thanks for sharing Simo Ahava & Jim van der Zalm!
