How does cloudflare measure workers success rate

For Workes & Pages, what is the name of the domain?

What is the error number?

502

What is the issue or error you’re encountering

SEMRush’s dashboard says that our website, proxied through Cloudflare Workers, returned error code 502. However, on the Cloudflare dashboard, it shows that we have a 100% success rate for requests. How does Cloudflare Workers calculate the success rate since these failures are not shown on the dashboard?