One of the unfortunate misunderstandings regarding the wonderful Google Tag Manager Preview mode is what it actually means when GTM reports “Tags Fired On This Event”. For many, this seems to indicate that whatever code the Tag was meant to execute also completed successfully. However, this is not the case.
Tip 19: Debugging Tag execution vs. actual requests Let’s get the distinction straight right away:
Google Tag Manager debug panel tells you when a Trigger has been invoked by certain conditions, and the Tag which uses this Trigger has its JavaScript injected into the Document Object Model.
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