Custom Plug in:
- The right URL is set in the custom plugin
- The Plugin Collects the right Head, Header and Footer content
- Tracking code is not set as a url; this is usually the ctm tracker.
Yoast:
- Select the right URL format for blogs eg: not- ys2%.html, yes- this-is-a-blog.html
- Make sure the Yoast is up to date with the updated Yoast settings.
- Make sure the Blog URL navigation matches the URL with the CMS template. Eg – /blog or /blog/ as required
- Verify Meta description is in place for Blog main page and individual blogs
Sometimes even after all changes blogs show as canonicalized, try deactivating Yoast in plugins and reactivating it and Optimize Yoast SEO to fix the crawl error