lego: Time Limit Exceeded with CloudFlare DNS

Hi,

I’m trying to use a DNS challenge with CloudFlare, but am getting: Time limit exceeded. Last error: NS laura.ns.cloudflare.com. did not return the expected TXT record

However, if I use dig to get the relevant TXT entry, it works (in real life I’m using the correct domain, not myhost.mydomain.com):

> dig _acme-challenge.myhost.mydomain.com txt @laura.ns.cloudflare.com

; <<>> DiG 9.10.3-P4-Ubuntu <<>> _acme-challenge.myhost.mydomain.com txt @laura.ns.cloudflare.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 27257
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;_acme-challenge.myhost.mydomain.com. IN	TXT

;; ANSWER SECTION:
_acme-challenge.myhost.mydomain.com. 120 IN	TXT	"<redacted>"

;; Query time: 368 msec
;; SERVER: 173.245.58.183#53(173.245.58.183)
;; WHEN: Thu Sep 21 13:49:17 IDT 2017
;; MSG SIZE  rcvd: 116

My Caddy version:

> caddy -version
Caddy 0.10.9

What am I missing? Thanks!