URLSession errorCode -1003

recently, i receive some feebacks There are two domain names in my app, the first domain name always reports error -1003(NRURLErrorCannotFindHost) ,at the same time the sencond domain does not report any error.

what is the problem? how to resolve this problem?

in documention, -1003 means host name can not be resolved. but the second domain has no error at the same thime

URLSession errorCode -1003
 
 
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