DNS problem: SERVFAIL for DNSSEC signed domain

I am seeing DNS issues for that domain.

If I check whois for your primary nameservers I get
lily.ns.cloudflare.com
theo.ns.cloudflare.com

If I try and query them for the IP address for your domain - I get a timeout
;; connection timed out; no servers could be reached

I’d guess that the one that worked fine wasn’t set up to use the cloudflare nameservers.