Description:

The documented keyboard shortcuts for navigating messages using Alt + Left Arrow, Alt + Right Arrow, Alt + Up Arrow, and Alt + Down Arrow do not seem to work as expected.

Steps to reproduce:

1. Try using the following shortcuts:
   Alt + Left Arrow (Move to the beginning of the message)
   Alt + Right Arrow (Move to the end of the message)
   Alt + Up Arrow (Move to the beginning of the message)
   Alt + Down Arrow (Move to the end of the message)

2. The expected functionality does not occur when pressing these key combinations.

Expected behavior:

The shortcuts should allow navigation within the message as described in the help prompt.

Actual behavior:

Pressing these shortcuts does not trigger any response.