Edu 2071 remove the general section of faqs

src/pages/docs/platform/errors/codes.mdx

@@ -599,6 +599,16 @@ The request will be automatically retried by the SDK.
 
 **Resolution:** If the client never connects to the [primary or fallback endpoints](https://faqs.ably.com/routing-around-network-and-dns-issues), check any firewall rules that may be blocking access to Ably's [endpoints](https://faqs.ably.com/if-i-need-to-whitelist-ablys-servers-from-a-firewall-which-ports-ips-and/or-domains-should-i-add).
 
+**Network connectivity detection:** Ably SDKs use `https://internet-up.ably-realtime.com/is-the-internet-up.txt` to test network connectivity when connection attempts fail. If CSP policies block this endpoint, ensure your Content Security Policy includes:
+
+<Code>
+```
+Content-Security-Policy: connect-src https://internet-up.ably-realtime.com; script-src https://internet-up.ably-realtime.com
+```
+</Code>
+
+Blocking this resource causes clients to assume they're offline and prevents fallback host usage.
+
 ## 80016: Operation on superseded connection <a id="80016"/>
 
 This error occurs when a browser [connection](/docs/connect/states#connection-states) upgrades from an HTTP (Comet) transport to WebSockets. It is logged by the client library when operations are performed on the older transport.