This was a combination of 522 and 524 errors. Please read the following to help you diagnose the issue:
https://developers.cloudflare.com/support/troubleshooting/cloudflare-errors/troubleshooting-cloudflare-5xx-errors/#error-522-connection-timed-out
https://developers.cloudflare.com/support/troubleshooting/cloudflare-errors/troubleshooting-cloudflare-5xx-errors/#error-524-a-timeout-occurred