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DNS_PROBE_FINISHED_NXDOMAIN

Hi,
I am newb to this, this is my first time that Im using web deployment and DNS domain configurations.
My website is hosting at AWS S3 and my domain is: 
When Im trying to enter this domain sometimes the website is up and sometimes i get this error :
Website error code DNS_PROBE_FINISHED_NXDOMAIN
 
When im trying to enter my domain from my android, i always get this error.
Why am I receiving a DNS_PROBE_FINISHED_NXDOMAIN code for my website and how can i fix it ?
 
Thank you!