Quad9 Seems to be down/wonky from DC area

I seem to be getting a mix of no response and responses without IPs for only some domains via Quad9. I've reverted to Cloudflare and all seems working... To wit:

user ~ % dig @9.9.9.9 register.gotowebinar.com

; <<>> DiG 9.10.6 <<>> @9.9.9.9 register.gotowebinar.com

; (1 server found)

;; global options: +cmd

;; connection timed out; no servers could be reached

user ~ % dig @9.9.9.9 www.sans.org

; <<>> DiG 9.10.6 <<>> @9.9.9.9 www.sans.org

; (1 server found)

;; global options: +cmd

;; Got answer:

;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 13279

;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:

; EDNS: version: 0, flags:; udp: 1232

;; QUESTION SECTION:

;www.sans.org. IN A

;; Query time: 35 msec

;; SERVER: 9.9.9.9#53(9.9.9.9))

;; WHEN: Wed Dec 16 12:49:57 EST 2020

;; MSG SIZE rcvd: 41