Message hover buttons (React, Edit, Reply) don't move with scroll
At the moment, if you hover over a message, buttons appear on the top-left corner of it. However, if you scroll while keeping your mouse hovered over the same message, you will see that the buttons stay where they originally were, instead of moving with the rest of the chat.
In this screenshot, I hovered over the message the cursor is currently on, and kept my cursor on that message as I scrolled up.