In the latest version of Discourse, the username and timestamp is closer to the top border of posts than the avatar, making them misaligned. The read marker is as before and thus also misaligned.
The bottom buttons in posts are 15 px from the bottom border. Avatar is 15 px from the top border.
I can only imagine this being unintentional, and you’re probably already aware of it. Didn’t know what to search for, so I apologise if already reported.