The name servers you set up aren’t propagating. That’s the problem.
It’s either that or you haven’t pointed your domains from your registrar to your nameservers. If you have in fact done that, the easiest way to fix it is to use Cloudflare for your DNS.
The fellow in the thread below had the same issue you do. He swore he had his nameservers and DNS set up properly. Turns out, he didn’t.
I told him to use Cloudflare and it’d be fixed in 10 minutes. He did eventually and it was.