Error 522 on my website

[user82311]

Hello, i have a problem.
error 522 on my website: https://grandfatherclock.ru/

I contacted the hosting provider Reg. ru, they reported that there was an error on the side of CloudFlare, to check they advised to change the DNS nameserver “maria.ns.cloudflare. com; matt.ns.cloudflare. com” to the default value "ns1.reg. ru; ns2.reg. ru "that I did and the site started working. Then I returned the nameserver to the Cloudflare settings - it doesn’t work again. Help, what needs to be done?

[matteo]

A 522 error typically happens when Cloudflare requests to the origin (your webserver) get blocked. Review the suggestions in this Community Tip for troubleshooting ideas.

[user82311]

Thank you so much, I will try to solve the problem with your advice.