Why tags don't fire
The GTM debug panel shows your tag sitting there, greyed out, never triggering. The most common reasons:
Trigger mismatch. Your trigger is set to "Form Submission" but the form uses JavaScript to submit data without a traditional form post. GTM never sees the event. This is incredibly common with modern form builders, AJAX forms, and single-page applications.
Wrong trigger type. You're using "Click" when you need "Form Submission", or "Page View" when you need "DOM Ready". Each trigger type fires at a different moment, and the wrong choice means the tag either fires too early, too late, or never.
Variable not resolving. Your trigger depends on a variable that isn't populated. Maybe the CSS selector changed, or the element ID was removed in a site update. The variable returns undefined, the trigger condition fails, and the tag stays silent.
Container not published. You made changes in the workspace but forgot to publish. Or someone published a different workspace that overwrote yours. GTM's versioning is powerful but it's easy to lose work.
The quick fix
Open the GTM preview panel. Navigate your site. Watch which triggers fire and which don't. Compare the expected trigger conditions with what's actually happening in the data layer. Fix the mismatch. Republish.
This works, until the next site update breaks something again.
The permanent fix
Stop using GTM for conversion tracking. Tagless doesn't use tags, triggers, or variables. There's nothing to fire. It detects conversion points on your site automatically and captures the data without any configuration.
When your site changes, Tagless adapts. No republishing. No debug panels. No tags sitting there, greyed out, silently losing your conversion data.