What is the reason why Weibo's private letter (chat) has been read but not marked?

Weibo's private message (chat) has been read but not marked for the following reasons:

1. After receiving the private message from the other party, Sina Weibo will not display the "read" mark in the private message from Weibo, the other party's mobile phone, as long as it doesn't need to open it with the mobile phone Weibo, but uses the computer to access the private message from Weibo to read the other party's message. This is true whether it is a voice private message or a text private message. But as long as you open the private message sent by the other party with your mobile phone, the other party will definitely see that you have clicked to read.

2, related to the sending time, or related to the reading time, almost the time is not marked.

3. Weibo sent a private chat message, which disappeared after refreshing, because the system made a default. First, the transmission was successful. Secondly, in the case of no reply, the system defaults to unread, which is convenient for prompting the user and patiently waiting for the other party not to go online.

4. If the other party reads it, it will display the information that the other party has read, or there is no hint of any information, which is convenient for private chat and more information.

5. Sina Weibo Information Sending Center may also make mistakes, but the information was sent and has been confirmed by the other party. If the other party receives the message but does not reply, the system automatically defaults to gray, and if it has been read, the system defaults to green.