Confusion with messages

I received a message this morning. I figured out who the sender was by the content and replied. Only then did I notice that the message had come from an anonymous user. There is a blank space above the sender and I still don't know if my reply actually went to the right recipient or just disappeared. I also don't know why this person's message wasn't saved with their other messages, but is in a separate folder as the only message.

manifestation of anomaly

Hello, the error was related to the sender's session expiring at the time of sending, the error has been fixed today. Unfortunately, your reply did not reach us.

I currently have 4 messages in the anonymous user folder. A strange anomaly. When my session timed out, the message I wrote simply disappeared and did not reach the recipient, but some people took special paths and a new anonymous folder was created so that the message would still arrive :) It was whatever it was, it's great that it's fixed now.