Do you have a local DNS resolver like pihole and create a DNS record there for your domain that points directly to a local resource? I got this error message when I switched to Origin certificates and had to remove the local DNS records to get it working again.
I got the problem WHEN I was using a local DNS resolver, which overwrote the DNS to a local ip address
www.example.de → overwritten to 192.168.80.2 (my proxy with origin certs) → Not working www.example.de → 220.127.116.11 (just a example of a public ip addresss of Cloudflare proxy) → my proxy (origin certs) Working
Btw, you can test if this is your problem:
nslookup www.example.de → will ask your local dns server
nslookup www.example.de 18.104.22.168 → will ask the Cloudflare dns server
But I can recommend PiHole as a local DNS resolver