We can use free Cloudflare to protect our site. However, If you encounter Error 522 is in Cloudflare, how to fix?
Here are two steps you should check:
1. Check your site is online or offline.
If your site is offline, Cloudflare will not connect your site. 522 error will generate.
2.Verify the DNS settings in your Cloudflare account are correct.
If the DNS settings in Cloudflare are wrong, Cloudflare will also not connect your site.
The detail is here.
https://support.cloudflare.com/hc/en-us/articles/200171906-Error-522-Connection-timed-out#keepalives