Troubleshooting Captcha Token Verification Failures After Return: Time Validity, Parameters, Injection, Score, and IP Layer-by-Layer Diagnosis

When a recognition service returns a token but the target site still rejects it, the failure usually falls into five categories: token expiration or reuse, mismatched sitekey/page URL/action/rqdata, token not injected or callback not triggered, reCAPTCHA v3/Enterprise score below threshold, or IP/session inconsistency between generation and submission. This article explains how to locate the failure layer and which log fields to record.