The domain is delegated towards ns1.dns-principal-30.com and ns2.dns-principal-30.com.
The two above name servers, ns1.dns-principal-30.com and ns2.dns-principal-30.com, are both responding with two NS records, that are pointing towards these .ns.cloudflare.com names.
If you require assistance with fixing these records, you will need to contact the operator of ns1.dns-principal-30.com and ns2.dns-principal-30.com.
Best you can do is to make sure they match the delegation in the parent registry, so I would update them to match ns1.dns-principal-30.com and ns2.dns-principal-30.com.
In dns-principal-30.com nameservers I don’t have any DNS directed to Cloudflare. Could it be the entity that registers the domain?
I think Cloudflare kept some old DNS, at some point it was configured in Cloudflare, but I don’t know which account registered it.
The NS records in those nameservers have now been corrected. Depending on when you changed it you will have to wait for the TTL to expire for the change to appear everywhere.