I have added a sub domain in digital ocean.My domain is registered in GoDaddy.

Domain : http://find-your-soul-sandwich.deliciousae.com/

Some times it is working fine but some times when it gives

This site can’t be reachedCheck if there is a typo in find-your-soul-sandwich.deliciousae.com.
DNS_PROBE_FINISHED_NXDOMAIN 

Here is the result of

dig @ns1.digitalocean.com deliciousae.com NS

;; ANSWER SECTION:
deliciousae.com.    1800    IN  NS  ns2.digitalocean.com.
deliciousae.com.    1800    IN  NS  ns3.digitalocean.com.
deliciousae.com.    1800    IN  NS  ns1.digitalocean.com.

click here to view image NS record

Here is the result of A record

dig find-your-soul-sandwich.deliciousae.com @ns1.digitalocean.com

;; ANSWER SECTION:
find-your-soul-sandwich.deliciousae.com. 3600 IN A 167.71.205.196

click here to view image A record

Please help me to solve this problem. Thanks is Advance.