As decribed in this post, I’ve moved away from Cloudflare, and turned back to Namecheap, where I bought the domain, for DNS managing.
However, it turned out that Namecheap does not support CNAME flattening. That is, I can’t use a CNAME record on the naked domain (i.e. nerde.pw) without breaking email MX records. (See this link for more details)
As such, the URL of this site will be changed to https://blog.nerde.pw/. The old URL http://nerde.pw/ will still redirect to the new page, but keep in mind that the old one does not allow HTTPS connections due to Namecheap URL forwarding not supporting it.
EDIT: I created a dummy Netlify site, which accepts HTTPS, at https://nerde.pw/ that redirects to the current one. However, it is still advised that you use the new URL in case of future changes.
The perspicacious reader might see that if I could create a site at the old URL, I could put this site there in the first place. However, the DNS records at the two domains are actually quite different. For the redirector at the naked domain, I only used an A record pointing to one of Netlify’s US servers. This potentially makes loading speeds slower, since it’s not taking full advantage of Netlify’s CDN. On the other hand, blog.nerde.pw uses CNAME record that points to Netlify’s domain, allowing it to return different IPs based on your location.