[Errors] Update error-500.mdx

SPM-2107

Author: ngayerie

src/content/docs/support/troubleshooting/http-status-codes/cloudflare-5xx-errors/error-500.mdx

@@ -25,4 +25,9 @@ However, if the `500` error contains `cloudflare` or `cloudflare-nginx` in the H
 :::note
 
 If you observe blank or white pages when visiting your website, confirm whether the issue occurs when [temporarily pausing Cloudflare](/fundamentals/manage-domains/pause-cloudflare/) and contact your hosting provider for assistance.
-:::
+:::
+
+### Known Cloudflare issue leading to HTTP Error 500
+
+- A configuration issue on Page Rules can generate HTTP Error 500 on the Cloudflare Edge. 
+See [the article under Page Rules](/rules/page-rules/troubleshooting/general/#error-500-internal-server-error) for more details and resolution.