Incorrect access and resolution of BC28 domain name

The BC28 domain name cannot be used to access huawei cloud platform, but IP can be used (coap protocol). At present, the project must be accessed by domain name. May I ask why not?I can’t use AT + QDNS to resolve the domain name, according to the example to resolve the baidu domain name is also returned error.

I have a similar problem with the BC66 module. I am using a similar command: AT+QIDNSGIP.