When using keyboard navigation in a chat, newer versions will have a box highlighting the selected message. Normally, the page will scroll to fully display the selected message, but if the message is too long and the window size is insufficient to show it completely, the page will scroll to a position where the bottom of the message box aligns with the bottom of the window, causing the upper part of the message to be out of view. If there are multiple consecutive long messages, this part of the content will always be skipped.
The options for messages are located in the middle on the right side of the message box, and this bug makes them more likely to stay out of the visible area.
The most serious problem is message loading, which is not continuous. There is a small blank area at the top of the page, and more messages are loaded when you scroll to it. However, because long messages can only be selected from the bottom, this area is never revealed, and messages do not continue to load.