Limit the findings in TYPO3
Compare routing output and web server normalization. If both force opposite forms, no additional rule on a single side helps.
Where to check the setting in TYPO3
Compare the generated route from site configuration and route enhancer with redirects on the web server and in EXT:redirects. Determine which path shape should apply. A path generated by the router must not be redirected to the other spelling by a downstream rule.
Example of this specific finding
Illustrative control case: /consultation and /consultation/ deliver the same content each with 200 and different canonicals. The file address /assets/app.js should be treated separately.
follow-up audit in TYPO3
Set the desired content URL and match links, canonical and forwarding to it. Test file and API paths as your own control cases.
Derogations and scope
With and without slash can be technically different resources. Do not use a global slash rule without checking the routing.
Reference: TYPO3 13.4 with EXT:seo. For other major versions and own extensions, responsibilities may differ; check the actually installed output.
Classify the general error
Definition, system-independent causes and further correction examples: Unify slash variants without losing file paths