FWIW, that request on my AWS test server gives:
dig @ns2.hostyonel.com +norecurse ulsyart.com caa
; <<>> DiG 9.11.4-P2-RedHat-9.11.4-26.P2.amzn2.5.2 <<>> @ns2.hostyonel.com +norecurse ulsyart.com caa
; (1 server found)
;; global options: +cmd
;; connection timed out; no servers could be reached