Does anyone else see the following?

When I move up and down messages in a message thread, organized by conversation, the message in the Preview window is not always the message highlighted in the list. This is not consistent, but most often it is one of my replies that is “stuck". One particular email, often the last one I sent, will repeat over and over as I move up or down the thread while other peoples replies will change as expected. Or Mail will ignore my replies and show the previous recipients mail instead of my reply. As a result, I can’t follow the actual conversation. This has been true for a long time though many iterations. I have found no particular pattern or cause.

FYI, my replies in the thread are BCCs to myself, not emails from the Sent folder though this does happen with emails from the Sent folder as well.