We have created a new website in our account however the site is getting different nameservers from the rest of the sites that share the same account which I find strange.
I am not sure if the issue is related but seems like when I do a Google search to see if any URLs got indexed I am seeing subdomains that have been indexed that look very suspicious and spam.
Did someone has the same experience? It looks very suspicious that someone hijacked the DNS somehow.
It is of the utmost importance that you do not change nameservers to Cloudflare nameservers until after they have been assigned in the dashboard of your Cloudflare account. While the same pair are often assigned across domains in an account, the assignment occurs on a per domain basis, which means that it is not safe to assume that you know the correct nameservers.