Error 1014 means you are CNAMEing to a target that’s not in your account. If this is to a host that also uses Cloudflare, it means that their end is not set up correctly.
The CNAME target is “sites.ludicrous.cloud” which is the location given by Gohighlevel to publish pages in this sub-domain. Before this, i added multiple CNAME records with different names under the same domain dns settings, all of them worked. So, I don’t think its from the target end.
Go High Level use Cloudflare-for-SaaS, so if you are getting a 1014 error then something is not configured correctly at the Go High Level end. You can try to remove your custom domain from there and re-add it, otherwise contact them.
Once working, you should also be able to proxy sites.ludicrous.cloud records so your Cloudflare settings can be applied to your site traffic, see…