the messages portal (CLOSED) (CLOSED)

Is there a problem with the messages portal? I regularly converse with a particular member of the website and I don't know if there's a way to run out of room or what, but the last message sent to him that shows up on the screen is dated March 17, 2022. Conversely the last message he sent, visible to me, is also the same date. Messages have been exchanged since then; I just received one he sent me an hour ago, but it doesn't show up on the screen. And I responded, and that doesn't show up either. I converse with other members of the site, and all current messages are visible.

I'm pretty sure I know what problem you're talking about. I have just discovered the same issue. 
It appears to be some kind of message limit or character limit, since it's only affecting longer conversations. 
This is definitely a bug, and I have already submitted a bug report.