Queries are sent to their server but they can not resolve them

Hello,
After changing the name servers, the site is completely turned off. "Can not find the IP address of the server

Queries are sent to their server but they can not resolve them.

All dns are well informed though.

Does anyone have a solution?

thanks in advance

Clearly the “Can not find the IP address” indicates some sort of DNS problem. Take another look at all DNS records on your old name server and make sure all of them are in your Cloudflare DNS page.

After checking all DNS are correct. Anything else can impact the site this way?

Based on the limited amount of information you provided, that’s my only guess. Do you know the hostname of the server it’s trying to reach?