Yesterday we upgraded our public DoH server from dnsdist 1.8.3 to 1.9.0 which resulted in a partial service outage for some of our users due to an issue in dnsdist. We downgraded to version 1.8.3 today and our DoH service should be back to normal. The PowerDNS developers assume this was: https://github.com/PowerDNS/pdns/issues/13850