GoDaddy Support sent me this information:
Thank you for your patience,
Regarding the 502 errors, these mean that the firewall has attempted to make a request to the hosting server but we have not received a response back. This could happen due to a variety of reasons:
- A security plugin is blocking access from our firewall IP addresses
- The hosting account may have hit its resource limits temporarily
- The hosting server may have been under load and couldn't respond in time
- Your web application may have triggered a Mod Security firewall rule on the hosting server
- The hosting server's firewall is blocking our firewall IP addresses
- Server exceeded a maximum number of simultaneous application or web server processes
USER ---->> FIREWALL ---->> SERVER 502<<-- <<-- <--no-response/block--
We are unable to see why the timeout happens, we can only see when it does. Normally, it can be due to the server being overloaded, it being misconfigured OR possibly blocking our IPs. There is more information on this issue here:
https://kb.sucuri.net/firewall/Troubleshooting/fixing-backend-timeout
Your web host will be able to correlate these timeouts with their own internal logs to determine why their hosting server is not responding to requests from the Firewall. The time zone of these errors is EST.
https://pastebin.sucuri.net/oiqfe3ab1rn
Let us know if we can be of further assistance.
With Regards,
Zane