Start by running [`LightningCMP.debug()`](/guides/verifying/) — most issues show
up in its hints.

## “A tag read consent state before a default was set” (GTM Preview)

A Google tag initialised before the Consent Mode default landed. Almost always a
**deferred-JS optimiser** reordering your scripts. Add `data-cfasync="false"` to
every Lightning `<script>` (Cloudflare Rocket Loader), or exclude them from WP
Rocket / LiteSpeed / NitroPack. If a **site-hosted** GTM/gtag tag is the culprit,
either move the inline `gtag('consent','default',{…denied…})` block above it or
let the CMP load the tag via [`bridges.google.tagId`](/integrations/bridges/#google-gtag--gtm).

## The banner doesn't appear

- The visitor's region may resolve to **no banner** (outside GDPR/US law), or a
  stored decision already exists — run `LightningCMP.reset()` to clear it.
- The page host may not be an **authorised domain** — the SDK no-ops off-domain.
  Check the dashboard; `localhost` is allowed for testing.

## A tracker still fires before consent

Either it's not gated (add the [script blocker](/integrations/script-blocker/)
markup or a bridge) or it's injected by GTM — gate it **inside GTM** via Consent
Settings, not by blocking the container.

## Analytics data dropped to zero

You probably hard-blocked a Google tag. [Bridge it](/integrations/bridges/#google-gtag--gtm)
instead so cookieless Consent Mode pings and modelling keep working.

:::note[More detail coming]
The full troubleshooting matrix is being migrated from `docs/INSTALL.md` §
_“Troubleshooting.”_
:::