Tencent shields .cn domain name in QQ chat messages?

Today, I heard several group friends say that links containing ".cn" cannot be sent via QQ messages. After experimenting with my two accounts, it turned out to be true.

Any message with a black dog bone in the middle indicates that it was not sent successfully (the message was sent from the right side to the left side). Regardless of whether it is recognized as a link or not, as long as it contains ".cn", it will be blocked. However, this does not include domains like "com.cn" or "net.cn". A standalone ".cn" can still be sent, but sending just this suffix in a message is meaningless.